{"id":683,"date":"2025-07-14T21:04:15","date_gmt":"2025-07-14T21:04:15","guid":{"rendered":"https:\/\/content.one.lumenlearning.com\/precalculus\/?post_type=chapter&#038;p=683"},"modified":"2025-12-16T15:40:24","modified_gmt":"2025-12-16T15:40:24","slug":"module-5-polynomial-equations-cheat-sheet","status":"publish","type":"chapter","link":"https:\/\/content.one.lumenlearning.com\/precalculus\/chapter\/module-5-polynomial-equations-cheat-sheet\/","title":{"raw":"Polynomial Equations: Cheat Sheet","rendered":"Polynomial Equations: Cheat Sheet"},"content":{"raw":"<h2 class=\"text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold\">Essential Concepts<\/h2>\r\n<h3 class=\"text-text-100 mt-2 -mb-1 text-base font-bold\">Dividing Polynomials<\/h3>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Polynomial long division works similarly to long division with numbers. We divide the leading terms, multiply, subtract, and repeat until we reach the end of the dividend.<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">The process:<\/p>\r\n\r\n<ol class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">Set up the division problem<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Divide the leading term of the dividend by the leading term of the divisor<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Multiply the answer by the divisor and write below like terms<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Subtract the bottom expression from the terms above<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Bring down the next term of the dividend<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Repeat steps 2-5 until reaching the last term<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Express any non-zero remainder as a fraction with the divisor as denominator<\/li>\r\n<\/ol>\r\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>The Division Algorithm<\/strong><\/h4>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">For polynomial <strong>dividend<\/strong> [latex]f(x)[\/latex] and non-zero <strong>divisor<\/strong> [latex]d(x)[\/latex]:<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">[latex]f(x) = d(x)q(x) + r(x)[\/latex]<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">where:<\/p>\r\n\r\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex]q(x)[\/latex] is the <strong>quotient<\/strong><\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex]r(x)[\/latex] is the <strong>remainder<\/strong> (degree less than [latex]d(x)[\/latex] or equals zero)<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">If [latex]r(x) = 0[\/latex], then [latex]d(x)[\/latex] divides evenly into [latex]f(x)[\/latex]<\/li>\r\n<\/ul>\r\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Synthetic Division<\/strong><\/h4>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Synthetic division is a shortcut for dividing polynomials by binomials of the form [latex]x - k[\/latex].<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Steps:<\/p>\r\n\r\n<ol class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">Write [latex]k[\/latex] for the divisor (if divisor is [latex]x + 2[\/latex], then [latex]k = -2[\/latex])<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Write coefficients of the dividend (use 0 for missing terms)<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Bring down the leading coefficient<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Multiply by [latex]k[\/latex] and write the product in the next column<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Add the terms in that column<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Repeat multiply-and-add process for remaining columns<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Bottom row gives quotient coefficients; last number is the remainder<\/li>\r\n<\/ol>\r\n<h3 class=\"text-text-100 mt-2 -mb-1 text-base font-bold\">Complex Numbers<\/h3>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Imaginary Numbers<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">The imaginary unit [latex]i[\/latex] is defined as [latex]i = \\sqrt{-1}[\/latex], which means [latex]i^2 = -1[\/latex].<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-pre-wrap leading-[1.7]\">Any square root of a negative number can be written as a multiple of [latex]i[\/latex]: [latex]\\sqrt{-25} = \\sqrt{25} \\cdot \\sqrt{-1} = 5i[\/latex]<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Complex Numbers<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">A complex number has the form [latex]a + bi[\/latex] where:<\/p>\r\n\r\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex]a[\/latex] is the real part<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex]b[\/latex] is the imaginary part (coefficient of [latex]i[\/latex])<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Both [latex]a[\/latex] and [latex]b[\/latex] are real numbers<\/li>\r\n<\/ul>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>The Complex Plane<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Complex numbers are plotted on a coordinate system where:<\/p>\r\n\r\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">Horizontal axis = real axis<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Vertical axis = imaginary axis<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">The complex number [latex]a + bi[\/latex] is plotted at point [latex](a, b)[\/latex]<\/li>\r\n<\/ul>\r\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Arithmetic with Complex Numbers<\/strong><\/h4>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Addition and Subtraction:<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Combine real parts and imaginary parts separately<\/p>\r\n\r\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex](a + bi) + (c + di) = (a + c) + (b + d)i[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex](a + bi) - (c + di) = (a - c) + (b - d)i[\/latex]<\/li>\r\n<\/ul>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Multiplication:<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Use the distributive property (FOIL), remembering that [latex]i^2 = -1[\/latex]<\/p>\r\n\r\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex](a + bi)(c + di) = (ac - bd) + (ad + bc)i[\/latex]<\/li>\r\n<\/ul>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Multiplying by a real number:<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Distribute to both parts<\/p>\r\n\r\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex]k(a + bi) = ka + kbi[\/latex]<\/li>\r\n<\/ul>\r\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Complex Conjugates<\/strong><\/h4>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">The complex conjugate of [latex]a + bi[\/latex] is [latex]a - bi[\/latex].<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">When you multiply complex conjugates, the result is always a real number:<\/p>\r\n\r\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex](a + bi)(a - bi) = a^2 + b^2[\/latex]<\/li>\r\n<\/ul>\r\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Powers of [latex]i[\/latex]<\/strong><\/h4>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">The powers of [latex]i[\/latex] cycle in a pattern of 4:<\/p>\r\n\r\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex]i^1 = i[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex]i^2 = -1[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex]i^3 = -i[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex]i^4 = 1[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex]i^5 = i[\/latex] (pattern repeats)<\/li>\r\n<\/ul>\r\n<h3 class=\"text-text-100 mt-2 -mb-1 text-base font-bold\">Zeros of Polynomial Functions<\/h3>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Remainder Theorem<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">If a polynomial [latex]f(x)[\/latex] is divided by [latex]x - k[\/latex], then the remainder is [latex]f(k)[\/latex].<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Factor Theorem<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">[latex]k[\/latex] is a zero of [latex]f(x)[\/latex] if and only if [latex](x - k)[\/latex] is a factor of [latex]f(x)[\/latex].<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">This means:<\/p>\r\n\r\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">If [latex]f(k) = 0[\/latex], then [latex](x - k)[\/latex] is a factor<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">If [latex](x - k)[\/latex] is a factor, then [latex]f(k) = 0[\/latex]<\/li>\r\n<\/ul>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Rational Zero Theorem<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">For polynomial [latex]f(x) = a_nx^n + a_{n-1}x^{n-1} + \\cdots + a_1x + a_0[\/latex] with integer coefficients:<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Every possible rational zero has the form [latex]\\frac{p}{q}[\/latex] where:<\/p>\r\n\r\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex]p[\/latex] is a factor of the constant term [latex]a_0[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex]q[\/latex] is a factor of the leading coefficient [latex]a_n[\/latex]<\/li>\r\n<\/ul>\r\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Finding Zeros of Polynomial Functions<\/strong><\/h4>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Steps:<\/p>\r\n\r\n<ol class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">Use the Rational Zero Theorem to list all possible rational zeros<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Use synthetic division to test each candidate\r\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">If remainder is 0, the candidate is a zero<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">If remainder is not 0, try the next candidate<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Continue until the quotient is quadratic<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Find remaining zeros using factoring or the quadratic formula<\/li>\r\n<\/ol>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Fundamental Theorem of Algebra<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Every polynomial function of degree [latex]n &gt; 0[\/latex] has at least one complex zero.<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">This means:<\/p>\r\n\r\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">A polynomial of degree [latex]n[\/latex] has exactly [latex]n[\/latex] zeros (counting multiplicities)<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">These zeros may be real or complex<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Real numbers are complex numbers with imaginary part equal to 0<\/li>\r\n<\/ul>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Linear Factorization Theorem<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">A polynomial function of degree [latex]n[\/latex] can be written as a product of [latex]n[\/latex] linear factors:<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">[latex]f(x) = a(x - c_1)(x - c_2) \\cdots (x - c_n)[\/latex]<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">where [latex]c_1, c_2, \\ldots, c_n[\/latex] are complex numbers (possibly including real numbers).<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Complex Conjugate Theorem<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">If a polynomial function [latex]f[\/latex] has real coefficients and [latex]a + bi[\/latex] (where [latex]b \\ne 0[\/latex]) is a zero, then the complex conjugate [latex]a - bi[\/latex] must also be a zero.<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><em>This means complex zeros always come in conjugate pairs for polynomials with real coefficients.<\/em><\/p>\r\n\r\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Writing Polynomials from Zeros<\/strong><\/h4>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Given zeros and a point on the graph:<\/p>\r\n\r\n<ol class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">Use the zeros to write linear factors [latex](x - c_1)(x - c_2) \\cdots[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">If a complex zero is given, include its conjugate<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Multiply the factors together: [latex]f(x) = a(\\text{factors})[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Use the given point to solve for the leading coefficient [latex]a[\/latex]<\/li>\r\n<\/ol>\r\n<h3 class=\"text-text-100 mt-2 -mb-1 text-base font-bold\">Polynomial Inequalities and Inverses<\/h3>\r\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Solving Polynomial Inequalities<\/strong><\/h4>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">To solve inequalities like [latex]f(x) &gt; 0[\/latex] or [latex]f(x) &lt; 0[\/latex]:<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Method 1 (Test Values):<\/p>\r\n\r\n<ol class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">Solve the equality [latex]f(x) = 0[\/latex] to find zeros<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Zeros divide the number line into intervals<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Choose a test value in each interval<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Evaluate [latex]f(\\text{test value})[\/latex] to determine if positive or negative<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Select intervals that satisfy the inequality<\/li>\r\n<\/ol>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Method 2 (Graphing):<\/p>\r\n\r\n<ol class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">Find zeros of the function<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Sketch the graph using end behavior and multiplicity<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Identify where the graph is above ([latex]&gt; 0[\/latex]) or below ([latex]&lt; 0[\/latex]) the x-axis<\/li>\r\n<\/ol>\r\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Inverse of Polynomial Functions<\/strong><\/h4>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Not all polynomial functions have inverses that are functions. A polynomial must be one-to-one (pass the horizontal line test) to have an inverse function.<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><em>Notation: [latex]f^{-1}(x)[\/latex] denotes the inverse function, NOT [latex]\\frac{1}{f(x)}[\/latex]<\/em><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Finding Inverses of One-to-One Polynomials<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Steps:<\/p>\r\n\r\n<ol class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">Verify the function is one-to-one<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Replace [latex]f(x)[\/latex] with [latex]y[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Interchange [latex]x[\/latex] and [latex]y[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Solve for [latex]y[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Rename as [latex]f^{-1}(x)[\/latex]<\/li>\r\n<\/ol>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Key properties:<\/p>\r\n\r\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex]f^{-1}(f(x)) = x[\/latex] for all [latex]x[\/latex] in the domain of [latex]f[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">[latex]f(f^{-1}(x)) = x[\/latex] for all [latex]x[\/latex] in the domain of [latex]f^{-1}[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Graphs of [latex]f[\/latex] and [latex]f^{-1}[\/latex] are reflections across the line [latex]y = x[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Domain of [latex]f[\/latex] = Range of [latex]f^{-1}[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Range of [latex]f[\/latex] = Domain of [latex]f^{-1}[\/latex]<\/li>\r\n<\/ul>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Restricting the Domain<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">When a polynomial is not one-to-one (like quadratic functions), we can restrict its domain to make it one-to-one, then find the inverse on that restricted domain.<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">For [latex]f(x) = (x - h)^2 + k[\/latex]:<\/p>\r\n\r\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\r\n \t<li class=\"whitespace-normal break-words pl-2\">Restrict to [latex]x \\ge h[\/latex] (right side): [latex]f^{-1}(x) = h + \\sqrt{x - k}[\/latex]<\/li>\r\n \t<li class=\"whitespace-normal break-words pl-2\">Restrict to [latex]x \\le h[\/latex] (left side): [latex]f^{-1}(x) = h - \\sqrt{x - k}[\/latex]<\/li>\r\n<\/ul>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">The outputs of the inverse must match the restricted domain of the original function.<\/p>\r\n\r\n<h2 class=\"text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold\">Key Equations<\/h2>\r\n<table>\r\n<tbody>\r\n<tr>\r\n<td><strong>Imaginary unit<\/strong><\/td>\r\n<td>[latex]i = \\sqrt{-1}[\/latex], therefore [latex]i^2 = -1[\/latex]<\/td>\r\n<\/tr>\r\n<tr>\r\n<td><strong>Complex number standard form<\/strong><\/td>\r\n<td>[latex]a + bi[\/latex]<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<h2>Glossary<\/h2>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>complex conjugate<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">the complex number in which the sign of the imaginary part is changed and the real part is left unchanged; when multiplied by or added to the original complex number, the result is a real number<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>complex number<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">a number of the form [latex]a + bi[\/latex] where [latex]a[\/latex] is the real part and [latex]bi[\/latex] is the imaginary part<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>complex plane<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">a coordinate system where the horizontal axis represents the real part and the vertical axis represents the imaginary part of a complex number<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Descartes' Rule of Signs<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">a rule that determines the maximum possible numbers of positive and negative real zeros based on the number of sign changes of [latex]f(x)[\/latex] and [latex]f(-x)[\/latex]<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Division Algorithm<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">given polynomial dividend [latex]f(x)[\/latex] and non-zero polynomial divisor [latex]d(x)[\/latex] where the degree of [latex]d(x)[\/latex] is less than or equal to the degree of [latex]f(x)[\/latex], there exist unique polynomials [latex]q(x)[\/latex] and [latex]r(x)[\/latex] such that [latex]f(x) = d(x)q(x) + r(x)[\/latex]<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Factor Theorem<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">[latex]k[\/latex] is a zero of polynomial function [latex]f(x)[\/latex] if and only if [latex](x - k)[\/latex] is a factor of [latex]f(x)[\/latex]<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Fundamental Theorem of Algebra<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">a polynomial function with degree greater than 0 has at least one complex zero<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>imaginary number<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">a number in the form [latex]bi[\/latex] where [latex]i = \\sqrt{-1}[\/latex]<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>invertible function<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">any function that has an inverse function<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Linear Factorization Theorem<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">allowing for multiplicities, a polynomial function will have the same number of factors as its degree, and each factor will be in the form [latex](x - c)[\/latex] where [latex]c[\/latex] is a complex number<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Rational Zero Theorem<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">the possible rational zeros of a polynomial function have the form [latex]\\frac{p}{q}[\/latex] where [latex]p[\/latex] is a factor of the constant term and [latex]q[\/latex] is a factor of the leading coefficient<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Remainder Theorem<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">if a polynomial [latex]f(x)[\/latex] is divided by [latex]x - k[\/latex], then the remainder is equal to the value [latex]f(k)[\/latex]<\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>synthetic division<\/strong><\/p>\r\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">a shortcut method that can be used to divide a polynomial by a binomial of the form [latex]x - k[\/latex]<\/p>","rendered":"<h2 class=\"text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold\">Essential Concepts<\/h2>\n<h3 class=\"text-text-100 mt-2 -mb-1 text-base font-bold\">Dividing Polynomials<\/h3>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Polynomial long division works similarly to long division with numbers. We divide the leading terms, multiply, subtract, and repeat until we reach the end of the dividend.<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">The process:<\/p>\n<ol class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">Set up the division problem<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Divide the leading term of the dividend by the leading term of the divisor<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Multiply the answer by the divisor and write below like terms<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Subtract the bottom expression from the terms above<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Bring down the next term of the dividend<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Repeat steps 2-5 until reaching the last term<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Express any non-zero remainder as a fraction with the divisor as denominator<\/li>\n<\/ol>\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>The Division Algorithm<\/strong><\/h4>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">For polynomial <strong>dividend<\/strong> [latex]f(x)[\/latex] and non-zero <strong>divisor<\/strong> [latex]d(x)[\/latex]:<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">[latex]f(x) = d(x)q(x) + r(x)[\/latex]<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">where:<\/p>\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">[latex]q(x)[\/latex] is the <strong>quotient<\/strong><\/li>\n<li class=\"whitespace-normal break-words pl-2\">[latex]r(x)[\/latex] is the <strong>remainder<\/strong> (degree less than [latex]d(x)[\/latex] or equals zero)<\/li>\n<li class=\"whitespace-normal break-words pl-2\">If [latex]r(x) = 0[\/latex], then [latex]d(x)[\/latex] divides evenly into [latex]f(x)[\/latex]<\/li>\n<\/ul>\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Synthetic Division<\/strong><\/h4>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Synthetic division is a shortcut for dividing polynomials by binomials of the form [latex]x - k[\/latex].<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Steps:<\/p>\n<ol class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">Write [latex]k[\/latex] for the divisor (if divisor is [latex]x + 2[\/latex], then [latex]k = -2[\/latex])<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Write coefficients of the dividend (use 0 for missing terms)<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Bring down the leading coefficient<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Multiply by [latex]k[\/latex] and write the product in the next column<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Add the terms in that column<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Repeat multiply-and-add process for remaining columns<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Bottom row gives quotient coefficients; last number is the remainder<\/li>\n<\/ol>\n<h3 class=\"text-text-100 mt-2 -mb-1 text-base font-bold\">Complex Numbers<\/h3>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Imaginary Numbers<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">The imaginary unit [latex]i[\/latex] is defined as [latex]i = \\sqrt{-1}[\/latex], which means [latex]i^2 = -1[\/latex].<\/p>\n<p class=\"font-claude-response-body break-words whitespace-pre-wrap leading-[1.7]\">Any square root of a negative number can be written as a multiple of [latex]i[\/latex]: [latex]\\sqrt{-25} = \\sqrt{25} \\cdot \\sqrt{-1} = 5i[\/latex]<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Complex Numbers<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">A complex number has the form [latex]a + bi[\/latex] where:<\/p>\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">[latex]a[\/latex] is the real part<\/li>\n<li class=\"whitespace-normal break-words pl-2\">[latex]b[\/latex] is the imaginary part (coefficient of [latex]i[\/latex])<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Both [latex]a[\/latex] and [latex]b[\/latex] are real numbers<\/li>\n<\/ul>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>The Complex Plane<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Complex numbers are plotted on a coordinate system where:<\/p>\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">Horizontal axis = real axis<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Vertical axis = imaginary axis<\/li>\n<li class=\"whitespace-normal break-words pl-2\">The complex number [latex]a + bi[\/latex] is plotted at point [latex](a, b)[\/latex]<\/li>\n<\/ul>\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Arithmetic with Complex Numbers<\/strong><\/h4>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Addition and Subtraction:<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Combine real parts and imaginary parts separately<\/p>\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">[latex](a + bi) + (c + di) = (a + c) + (b + d)i[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">[latex](a + bi) - (c + di) = (a - c) + (b - d)i[\/latex]<\/li>\n<\/ul>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Multiplication:<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Use the distributive property (FOIL), remembering that [latex]i^2 = -1[\/latex]<\/p>\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">[latex](a + bi)(c + di) = (ac - bd) + (ad + bc)i[\/latex]<\/li>\n<\/ul>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Multiplying by a real number:<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Distribute to both parts<\/p>\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">[latex]k(a + bi) = ka + kbi[\/latex]<\/li>\n<\/ul>\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Complex Conjugates<\/strong><\/h4>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">The complex conjugate of [latex]a + bi[\/latex] is [latex]a - bi[\/latex].<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">When you multiply complex conjugates, the result is always a real number:<\/p>\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">[latex](a + bi)(a - bi) = a^2 + b^2[\/latex]<\/li>\n<\/ul>\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Powers of [latex]i[\/latex]<\/strong><\/h4>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">The powers of [latex]i[\/latex] cycle in a pattern of 4:<\/p>\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">[latex]i^1 = i[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">[latex]i^2 = -1[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">[latex]i^3 = -i[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">[latex]i^4 = 1[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">[latex]i^5 = i[\/latex] (pattern repeats)<\/li>\n<\/ul>\n<h3 class=\"text-text-100 mt-2 -mb-1 text-base font-bold\">Zeros of Polynomial Functions<\/h3>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Remainder Theorem<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">If a polynomial [latex]f(x)[\/latex] is divided by [latex]x - k[\/latex], then the remainder is [latex]f(k)[\/latex].<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Factor Theorem<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">[latex]k[\/latex] is a zero of [latex]f(x)[\/latex] if and only if [latex](x - k)[\/latex] is a factor of [latex]f(x)[\/latex].<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">This means:<\/p>\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">If [latex]f(k) = 0[\/latex], then [latex](x - k)[\/latex] is a factor<\/li>\n<li class=\"whitespace-normal break-words pl-2\">If [latex](x - k)[\/latex] is a factor, then [latex]f(k) = 0[\/latex]<\/li>\n<\/ul>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Rational Zero Theorem<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">For polynomial [latex]f(x) = a_nx^n + a_{n-1}x^{n-1} + \\cdots + a_1x + a_0[\/latex] with integer coefficients:<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Every possible rational zero has the form [latex]\\frac{p}{q}[\/latex] where:<\/p>\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">[latex]p[\/latex] is a factor of the constant term [latex]a_0[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">[latex]q[\/latex] is a factor of the leading coefficient [latex]a_n[\/latex]<\/li>\n<\/ul>\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Finding Zeros of Polynomial Functions<\/strong><\/h4>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Steps:<\/p>\n<ol class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">Use the Rational Zero Theorem to list all possible rational zeros<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Use synthetic division to test each candidate\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">If remainder is 0, the candidate is a zero<\/li>\n<li class=\"whitespace-normal break-words pl-2\">If remainder is not 0, try the next candidate<\/li>\n<\/ul>\n<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Continue until the quotient is quadratic<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Find remaining zeros using factoring or the quadratic formula<\/li>\n<\/ol>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Fundamental Theorem of Algebra<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Every polynomial function of degree [latex]n > 0[\/latex] has at least one complex zero.<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">This means:<\/p>\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">A polynomial of degree [latex]n[\/latex] has exactly [latex]n[\/latex] zeros (counting multiplicities)<\/li>\n<li class=\"whitespace-normal break-words pl-2\">These zeros may be real or complex<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Real numbers are complex numbers with imaginary part equal to 0<\/li>\n<\/ul>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Linear Factorization Theorem<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">A polynomial function of degree [latex]n[\/latex] can be written as a product of [latex]n[\/latex] linear factors:<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">[latex]f(x) = a(x - c_1)(x - c_2) \\cdots (x - c_n)[\/latex]<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">where [latex]c_1, c_2, \\ldots, c_n[\/latex] are complex numbers (possibly including real numbers).<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Complex Conjugate Theorem<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">If a polynomial function [latex]f[\/latex] has real coefficients and [latex]a + bi[\/latex] (where [latex]b \\ne 0[\/latex]) is a zero, then the complex conjugate [latex]a - bi[\/latex] must also be a zero.<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><em>This means complex zeros always come in conjugate pairs for polynomials with real coefficients.<\/em><\/p>\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Writing Polynomials from Zeros<\/strong><\/h4>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Given zeros and a point on the graph:<\/p>\n<ol class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">Use the zeros to write linear factors [latex](x - c_1)(x - c_2) \\cdots[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">If a complex zero is given, include its conjugate<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Multiply the factors together: [latex]f(x) = a(\\text{factors})[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Use the given point to solve for the leading coefficient [latex]a[\/latex]<\/li>\n<\/ol>\n<h3 class=\"text-text-100 mt-2 -mb-1 text-base font-bold\">Polynomial Inequalities and Inverses<\/h3>\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Solving Polynomial Inequalities<\/strong><\/h4>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">To solve inequalities like [latex]f(x) > 0[\/latex] or [latex]f(x) < 0[\/latex]:<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Method 1 (Test Values):<\/p>\n<ol class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">Solve the equality [latex]f(x) = 0[\/latex] to find zeros<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Zeros divide the number line into intervals<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Choose a test value in each interval<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Evaluate [latex]f(\\text{test value})[\/latex] to determine if positive or negative<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Select intervals that satisfy the inequality<\/li>\n<\/ol>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Method 2 (Graphing):<\/p>\n<ol class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">Find zeros of the function<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Sketch the graph using end behavior and multiplicity<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Identify where the graph is above ([latex]> 0[\/latex]) or below ([latex]< 0[\/latex]) the x-axis<\/li>\n<\/ol>\n<h4 class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Inverse of Polynomial Functions<\/strong><\/h4>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Not all polynomial functions have inverses that are functions. A polynomial must be one-to-one (pass the horizontal line test) to have an inverse function.<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><em>Notation: [latex]f^{-1}(x)[\/latex] denotes the inverse function, NOT [latex]\\frac{1}{f(x)}[\/latex]<\/em><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Finding Inverses of One-to-One Polynomials<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Steps:<\/p>\n<ol class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-decimal flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">Verify the function is one-to-one<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Replace [latex]f(x)[\/latex] with [latex]y[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Interchange [latex]x[\/latex] and [latex]y[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Solve for [latex]y[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Rename as [latex]f^{-1}(x)[\/latex]<\/li>\n<\/ol>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">Key properties:<\/p>\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">[latex]f^{-1}(f(x)) = x[\/latex] for all [latex]x[\/latex] in the domain of [latex]f[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">[latex]f(f^{-1}(x)) = x[\/latex] for all [latex]x[\/latex] in the domain of [latex]f^{-1}[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Graphs of [latex]f[\/latex] and [latex]f^{-1}[\/latex] are reflections across the line [latex]y = x[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Domain of [latex]f[\/latex] = Range of [latex]f^{-1}[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Range of [latex]f[\/latex] = Domain of [latex]f^{-1}[\/latex]<\/li>\n<\/ul>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Restricting the Domain<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">When a polynomial is not one-to-one (like quadratic functions), we can restrict its domain to make it one-to-one, then find the inverse on that restricted domain.<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">For [latex]f(x) = (x - h)^2 + k[\/latex]:<\/p>\n<ul class=\"[li_&amp;]:mb-0 [li_&amp;]:mt-1.5 [li_&amp;]:gap-1.5 [&amp;:not(:last-child)_ul]:pb-1 [&amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-2 pl-8 mb-3\">\n<li class=\"whitespace-normal break-words pl-2\">Restrict to [latex]x \\ge h[\/latex] (right side): [latex]f^{-1}(x) = h + \\sqrt{x - k}[\/latex]<\/li>\n<li class=\"whitespace-normal break-words pl-2\">Restrict to [latex]x \\le h[\/latex] (left side): [latex]f^{-1}(x) = h - \\sqrt{x - k}[\/latex]<\/li>\n<\/ul>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">The outputs of the inverse must match the restricted domain of the original function.<\/p>\n<h2 class=\"text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold\">Key Equations<\/h2>\n<table>\n<tbody>\n<tr>\n<td><strong>Imaginary unit<\/strong><\/td>\n<td>[latex]i = \\sqrt{-1}[\/latex], therefore [latex]i^2 = -1[\/latex]<\/td>\n<\/tr>\n<tr>\n<td><strong>Complex number standard form<\/strong><\/td>\n<td>[latex]a + bi[\/latex]<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Glossary<\/h2>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>complex conjugate<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">the complex number in which the sign of the imaginary part is changed and the real part is left unchanged; when multiplied by or added to the original complex number, the result is a real number<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>complex number<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">a number of the form [latex]a + bi[\/latex] where [latex]a[\/latex] is the real part and [latex]bi[\/latex] is the imaginary part<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>complex plane<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">a coordinate system where the horizontal axis represents the real part and the vertical axis represents the imaginary part of a complex number<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Descartes&#8217; Rule of Signs<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">a rule that determines the maximum possible numbers of positive and negative real zeros based on the number of sign changes of [latex]f(x)[\/latex] and [latex]f(-x)[\/latex]<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Division Algorithm<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">given polynomial dividend [latex]f(x)[\/latex] and non-zero polynomial divisor [latex]d(x)[\/latex] where the degree of [latex]d(x)[\/latex] is less than or equal to the degree of [latex]f(x)[\/latex], there exist unique polynomials [latex]q(x)[\/latex] and [latex]r(x)[\/latex] such that [latex]f(x) = d(x)q(x) + r(x)[\/latex]<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Factor Theorem<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">[latex]k[\/latex] is a zero of polynomial function [latex]f(x)[\/latex] if and only if [latex](x - k)[\/latex] is a factor of [latex]f(x)[\/latex]<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Fundamental Theorem of Algebra<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">a polynomial function with degree greater than 0 has at least one complex zero<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>imaginary number<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">a number in the form [latex]bi[\/latex] where [latex]i = \\sqrt{-1}[\/latex]<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>invertible function<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">any function that has an inverse function<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Linear Factorization Theorem<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">allowing for multiplicities, a polynomial function will have the same number of factors as its degree, and each factor will be in the form [latex](x - c)[\/latex] where [latex]c[\/latex] is a complex number<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Rational Zero Theorem<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">the possible rational zeros of a polynomial function have the form [latex]\\frac{p}{q}[\/latex] where [latex]p[\/latex] is a factor of the constant term and [latex]q[\/latex] is a factor of the leading coefficient<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>Remainder Theorem<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">if a polynomial [latex]f(x)[\/latex] is divided by [latex]x - k[\/latex], then the remainder is equal to the value [latex]f(k)[\/latex]<\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"><strong>synthetic division<\/strong><\/p>\n<p class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\">a shortcut method that can be used to divide a polynomial by a binomial of the form [latex]x - k[\/latex]<\/p>\n","protected":false},"author":67,"menu_order":1,"template":"","meta":{"_candela_citation":"[]","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"part":506,"module-header":"cheat_sheet","content_attributions":[],"internal_book_links":[],"video_content":null,"cc_video_embed_content":{"cc_scripts":"","media_targets":[]},"try_it_collection":null,"_links":{"self":[{"href":"https:\/\/content.one.lumenlearning.com\/precalculus\/wp-json\/pressbooks\/v2\/chapters\/683"}],"collection":[{"href":"https:\/\/content.one.lumenlearning.com\/precalculus\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/content.one.lumenlearning.com\/precalculus\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/precalculus\/wp-json\/wp\/v2\/users\/67"}],"version-history":[{"count":7,"href":"https:\/\/content.one.lumenlearning.com\/precalculus\/wp-json\/pressbooks\/v2\/chapters\/683\/revisions"}],"predecessor-version":[{"id":5104,"href":"https:\/\/content.one.lumenlearning.com\/precalculus\/wp-json\/pressbooks\/v2\/chapters\/683\/revisions\/5104"}],"part":[{"href":"https:\/\/content.one.lumenlearning.com\/precalculus\/wp-json\/pressbooks\/v2\/parts\/506"}],"metadata":[{"href":"https:\/\/content.one.lumenlearning.com\/precalculus\/wp-json\/pressbooks\/v2\/chapters\/683\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/content.one.lumenlearning.com\/precalculus\/wp-json\/wp\/v2\/media?parent=683"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/precalculus\/wp-json\/pressbooks\/v2\/chapter-type?post=683"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/precalculus\/wp-json\/wp\/v2\/contributor?post=683"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/precalculus\/wp-json\/wp\/v2\/license?post=683"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}