{"id":2899,"date":"2024-06-10T19:17:43","date_gmt":"2024-06-10T19:17:43","guid":{"rendered":"https:\/\/content.one.lumenlearning.com\/calculus1\/?post_type=chapter&#038;p=2899"},"modified":"2024-08-05T01:52:45","modified_gmt":"2024-08-05T01:52:45","slug":"derivatives-as-rates-of-change-learn-it-3","status":"publish","type":"chapter","link":"https:\/\/content.one.lumenlearning.com\/calculus1\/chapter\/derivatives-as-rates-of-change-learn-it-3\/","title":{"raw":"Derivatives as Rates of Change: Learn It 3","rendered":"Derivatives as Rates of Change: Learn It 3"},"content":{"raw":"<h2>Rate of Change Applications Cont.<\/h2>\r\n<h3>Population Change<\/h3>\r\n<p id=\"fs-id1169736660717\">In addition to analyzing velocity, speed, acceleration, and position, we can use derivatives to analyze various types of populations, including those as diverse as bacteria colonies and cities. We can use a current population, together with a growth rate, to estimate the size of a population in the future. <br \/>\r\n<br \/>\r\nThe <strong>population growth rate<\/strong> is the rate of change of a population and consequently can be represented by the derivative of the size of the population.<\/p>\r\n<section class=\"textbox keyTakeaway\">\r\n<h3>population growth rate<\/h3>\r\n<p>If [latex]P(t)[\/latex] is the number of entities present in a population, then the population growth rate of [latex]P(t)[\/latex] is defined to be [latex]P^{\\prime}(t)[\/latex].<\/p>\r\n<\/section>\r\n<section class=\"textbox example\">\r\n<p id=\"fs-id1169739300220\">The population of a city is tripling every [latex]5[\/latex] years. If its current population is [latex]10,000[\/latex], what will be its approximate population [latex]2[\/latex] years from now?<\/p>\r\n<p>[reveal-answer q=\"fs-id1169739299610\"]Show Solution[\/reveal-answer]<br \/>\r\n[hidden-answer a=\"fs-id1169739299610\"]<\/p>\r\n<p id=\"fs-id1169739299610\">Let [latex]P(t)[\/latex] be the population (in thousands) [latex]t[\/latex] years from now. Thus, we know that [latex]P(0)=10[\/latex] and based on the information, we anticipate [latex]P(5)=30[\/latex]. Now estimate [latex]P^{\\prime}(0)[\/latex], the current growth rate, using<\/p>\r\n<div id=\"fs-id1169736589175\" class=\"equation unnumbered\" style=\"text-align: center;\">[latex]P^{\\prime}(0)\\approx \\frac{P(5)-P(0)}{5-0}=\\frac{30-10}{5}=4[\/latex].<\/div>\r\n<p id=\"fs-id1169739201103\">By applying the average rate of change formula to [latex]P(t)[\/latex], we can estimate the population [latex]2[\/latex] years from now by writing<\/p>\r\n<div id=\"fs-id1169736662465\" class=\"equation unnumbered\" style=\"text-align: center;\">[latex]P(2)\\approx P(0)+(2)P^{\\prime}(0)\\approx 10+2(4)=18[\/latex];<\/div>\r\n<p id=\"fs-id1169736662775\">thus, in [latex]2[\/latex] years the population will be approximately [latex]18,000[\/latex].<\/p>\r\n<p>Watch the following video to see the worked solution to this example.<\/p>\r\n<center><iframe title=\"YouTube video player\" src=\"https:\/\/www.youtube.com\/embed\/XOgb95xhWF0?controls=0&amp;start=981&amp;end=1123&amp;autoplay=0\" width=\"750\" height=\"450\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\" data-mce-fragment=\"1\"><\/iframe><\/center>\r\n<p>For closed captioning, open the video on its original page by clicking the Youtube logo in the lower right-hand corner of the video display. In YouTube, the video will begin at the same starting point as this clip, but will continue playing until the very end.<\/p>\r\n<p>You can view the <a href=\"https:\/\/oerfiles.s3.us-west-2.amazonaws.com\/Calculus\/Calculus1+Videos\/3.4DerivativesAsRatesOfChange981to1123_transcript.txt\" target=\"_blank\" rel=\"noopener\">transcript for this segmented clip of \"3.4 Derivatives as Rates of Change\" here (opens in new window)<\/a>.<\/p>\r\n<p>[\/hidden-answer]<\/p>\r\n<\/section>\r\n<div id=\"fs-id1169739202491\" class=\"textbook key-takeaways\">\r\n<p>&nbsp;<\/p>\r\n<\/div>","rendered":"<h2>Rate of Change Applications Cont.<\/h2>\n<h3>Population Change<\/h3>\n<p id=\"fs-id1169736660717\">In addition to analyzing velocity, speed, acceleration, and position, we can use derivatives to analyze various types of populations, including those as diverse as bacteria colonies and cities. We can use a current population, together with a growth rate, to estimate the size of a population in the future. <\/p>\n<p>The <strong>population growth rate<\/strong> is the rate of change of a population and consequently can be represented by the derivative of the size of the population.<\/p>\n<section class=\"textbox keyTakeaway\">\n<h3>population growth rate<\/h3>\n<p>If [latex]P(t)[\/latex] is the number of entities present in a population, then the population growth rate of [latex]P(t)[\/latex] is defined to be [latex]P^{\\prime}(t)[\/latex].<\/p>\n<\/section>\n<section class=\"textbox example\">\n<p id=\"fs-id1169739300220\">The population of a city is tripling every [latex]5[\/latex] years. If its current population is [latex]10,000[\/latex], what will be its approximate population [latex]2[\/latex] years from now?<\/p>\n<p><div class=\"qa-wrapper\" style=\"display: block\"><button class=\"show-answer show-answer-button collapsed\" data-target=\"qfs-id1169739299610\">Show Solution<\/button><\/p>\n<div id=\"qfs-id1169739299610\" class=\"hidden-answer\" style=\"display: none\">\n<p id=\"fs-id1169739299610\">Let [latex]P(t)[\/latex] be the population (in thousands) [latex]t[\/latex] years from now. Thus, we know that [latex]P(0)=10[\/latex] and based on the information, we anticipate [latex]P(5)=30[\/latex]. Now estimate [latex]P^{\\prime}(0)[\/latex], the current growth rate, using<\/p>\n<div id=\"fs-id1169736589175\" class=\"equation unnumbered\" style=\"text-align: center;\">[latex]P^{\\prime}(0)\\approx \\frac{P(5)-P(0)}{5-0}=\\frac{30-10}{5}=4[\/latex].<\/div>\n<p id=\"fs-id1169739201103\">By applying the average rate of change formula to [latex]P(t)[\/latex], we can estimate the population [latex]2[\/latex] years from now by writing<\/p>\n<div id=\"fs-id1169736662465\" class=\"equation unnumbered\" style=\"text-align: center;\">[latex]P(2)\\approx P(0)+(2)P^{\\prime}(0)\\approx 10+2(4)=18[\/latex];<\/div>\n<p id=\"fs-id1169736662775\">thus, in [latex]2[\/latex] years the population will be approximately [latex]18,000[\/latex].<\/p>\n<p>Watch the following video to see the worked solution to this example.<\/p>\n<div style=\"text-align: center;\"><iframe loading=\"lazy\" title=\"YouTube video player\" src=\"https:\/\/www.youtube.com\/embed\/XOgb95xhWF0?controls=0&amp;start=981&amp;end=1123&amp;autoplay=0\" width=\"750\" height=\"450\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\" data-mce-fragment=\"1\"><\/iframe><\/div>\n<p>For closed captioning, open the video on its original page by clicking the Youtube logo in the lower right-hand corner of the video display. In YouTube, the video will begin at the same starting point as this clip, but will continue playing until the very end.<\/p>\n<p>You can view the <a href=\"https:\/\/oerfiles.s3.us-west-2.amazonaws.com\/Calculus\/Calculus1+Videos\/3.4DerivativesAsRatesOfChange981to1123_transcript.txt\" target=\"_blank\" rel=\"noopener\">transcript for this segmented clip of &#8220;3.4 Derivatives as Rates of Change&#8221; here (opens in new window)<\/a>.<\/p>\n<\/div>\n<\/div>\n<\/section>\n<div id=\"fs-id1169739202491\" class=\"textbook key-takeaways\">\n<p>&nbsp;<\/p>\n<\/div>\n","protected":false},"author":15,"menu_order":25,"template":"","meta":{"_candela_citation":"[]","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"part":503,"module-header":"learn_it","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\/calculus1\/wp-json\/pressbooks\/v2\/chapters\/2899"}],"collection":[{"href":"https:\/\/content.one.lumenlearning.com\/calculus1\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/content.one.lumenlearning.com\/calculus1\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/calculus1\/wp-json\/wp\/v2\/users\/15"}],"version-history":[{"count":4,"href":"https:\/\/content.one.lumenlearning.com\/calculus1\/wp-json\/pressbooks\/v2\/chapters\/2899\/revisions"}],"predecessor-version":[{"id":2917,"href":"https:\/\/content.one.lumenlearning.com\/calculus1\/wp-json\/pressbooks\/v2\/chapters\/2899\/revisions\/2917"}],"part":[{"href":"https:\/\/content.one.lumenlearning.com\/calculus1\/wp-json\/pressbooks\/v2\/parts\/503"}],"metadata":[{"href":"https:\/\/content.one.lumenlearning.com\/calculus1\/wp-json\/pressbooks\/v2\/chapters\/2899\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/content.one.lumenlearning.com\/calculus1\/wp-json\/wp\/v2\/media?parent=2899"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/calculus1\/wp-json\/pressbooks\/v2\/chapter-type?post=2899"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/calculus1\/wp-json\/wp\/v2\/contributor?post=2899"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/calculus1\/wp-json\/wp\/v2\/license?post=2899"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}