{"id":31822,"date":"2019-12-21T17:40:34","date_gmt":"2019-12-21T22:40:34","guid":{"rendered":"https:\/\/www.myedme.com\/login\/?p=31822"},"modified":"2019-12-22T09:02:04","modified_gmt":"2019-12-22T14:02:04","slug":"finding-an-inverse-function","status":"publish","type":"post","link":"https:\/\/myedme.com\/login\/finding-an-inverse-function\/","title":{"rendered":"Finding an Inverse Function"},"content":{"rendered":"\n<p>Functions take <em>x<\/em> values to <em>y<\/em> values. Inverse functions reverse the direction. Now <em>y<\/em> values go to <em>x<\/em> values. <\/p>\n\n\n\n<p>Some equations are easy to find the inverse of others because it is easy to see how to reverse the function for all values.  <\/p>\n\n\n\n<p>Here are 3 examples of increasing complexity:<\/p>\n\n\n\n<ol class=\"wp-block-list\"><li>If <em>f<\/em>(<em>x<\/em>) = <em>x<\/em> + 3, then we can reverse the function by solving  <em>x <\/em>=<em> f<\/em>(<em>x<\/em>) + 3  for  <em>f<\/em>(<em>x<\/em>), which is  <em>f<\/em>(<em>x<\/em>) = <em>x<\/em> &#8211; 3. <\/li><\/ol>\n\n\n\n<p><\/p>\n\n\n\n<p>2. If  <em>f<\/em>(<em>x<\/em>) = 5<em>x<\/em>, then we can reverse the function by solving  <em>x<\/em> = 5 <em>f<\/em>(<em>x<\/em>) for  <em>f<\/em>(<em>x<\/em>), which is  <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=+++f%28x%29+%3D+%5Cfrac%7Bx%7D%7B5%7D+&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"   f(x) = &#92;frac{x}{5} \" class=\"latex\" \/><\/p>\n\n\n\n<p>  3. If <em>f<\/em>(<em>x<\/em>)=<em>x<\/em><sup>3<\/sup>, then we can reverse the function by solving for <em>x<\/em> = (<em>f<\/em>(<em>x<\/em>))<sup>3<\/sup> which is <\/p>\n\n\n\n<img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=+++f%28x%29+%3D+%5Csqrt%5B3%5D%7Bx%7D+&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"   f(x) = &#92;sqrt[3]{x} \" class=\"latex\" \/>\n\n\n\n<p><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Same Content from <a rel=\"noreferrer noopener\" aria-label=\"OpenStax (opens in a new tab)\" href=\"https:\/\/openstax.org\/books\/calculus-volume-1\/pages\/1-4-inverse-functions#3901\" target=\"_blank\">OpenStax<\/a><\/h3>\n\n\n\n<p>We can now consider one-to-one functions and show how to find their inverses. Recall that a function maps elements in the domain of&nbsp;<em>f<\/em> to elements in the range of&nbsp;<em>f<\/em>.&nbsp;The inverse function maps each element from the range of&nbsp;<em>f<\/em>&nbsp;back to its corresponding element from the domain of&nbsp;<em>f<\/em>.&nbsp;Therefore, to find the inverse function of a one-to-one function&nbsp;<em>f<\/em>,&nbsp;given any&nbsp;<em>y<\/em>&nbsp;in the range of&nbsp;<em>f<\/em>,&nbsp;we need to determine which&nbsp;<em>x<\/em> in the domain of&nbsp;<em>f<\/em>&nbsp;satisfies&nbsp;<em>f<\/em>(<em>x<\/em>)=<em>y<\/em>.&nbsp;Since&nbsp;<em>f<\/em>&nbsp;is one-to-one, there is exactly one such value&nbsp;<em>x<\/em>.&nbsp;We can find that value&nbsp;<em>x<\/em>&nbsp;by solving the equation&nbsp;<em>f<\/em>(<em>x<\/em>)=<em>y<\/em>&nbsp;for&nbsp;<em>x<\/em>.&nbsp;Doing so, we are able to write&nbsp;<em>x<\/em>&nbsp;as a function of&nbsp;<em>y<\/em>&nbsp;where the domain of this function is the range of&nbsp;<em>f<\/em>&nbsp;and the range of this new function is the domain of&nbsp;<em>f<\/em>.&nbsp;Consequently, this function is the inverse of&nbsp;<em>f<\/em>,&nbsp;and we write&nbsp;<em>x<\/em>=<em>f<\/em><sup>\u22121<\/sup>(<em>y<\/em>).&nbsp;Since we typically use the variable&nbsp;<em>x<\/em>&nbsp;to denote the independent variable and&nbsp;<em>y<\/em>&nbsp;to denote the dependent variable, we often interchange the roles of&nbsp;<em>x<\/em>&nbsp;and&nbsp;<em>y<\/em>,&nbsp;and write&nbsp;<em>y<\/em>=<em>f<\/em><sup>\u22121<\/sup>(<em>x<\/em>).&nbsp;Representing the inverse function in this way is also helpful later when we graph a function&nbsp;<em>f<\/em>&nbsp;and its inverse&nbsp;<em>f<\/em><sup>\u22121<\/sup>&nbsp;on the same axes.<\/p>\n\n\n\n<p>PROBLEM-SOLVING STRATEGY: FINDING AN INVERSE FUNCTION<\/p>\n\n\n\n<ol class=\"wp-block-list\"><li>Solve the equation\u00a0<em>y<\/em>=<em>f<\/em>(<em>x<\/em>)\u00a0for\u00a0<em>x<\/em>.<\/li><li>Interchange the variables\u00a0<em>x<\/em>\u00a0and\u00a0<em>y<\/em>\u00a0and write\u00a0<em>y<\/em>=<em>f<\/em>\u22121(<em>x<\/em>).<\/li><\/ol>\n","protected":false},"excerpt":{"rendered":"<p>Functions take x values to y values. Inverse functions reverse the direction. Now y values go to x values. Some equations are easy to find the inverse of others because it is easy to see how to reverse the function for all values. Here are 3 examples of increasing complexity: If f(x) = x + [&hellip;]<\/p>\n","protected":false},"author":11,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"nf_dc_page":"","_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-31822","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/myedme.com\/login\/wp-json\/wp\/v2\/posts\/31822","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/myedme.com\/login\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/myedme.com\/login\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/myedme.com\/login\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/myedme.com\/login\/wp-json\/wp\/v2\/comments?post=31822"}],"version-history":[{"count":4,"href":"https:\/\/myedme.com\/login\/wp-json\/wp\/v2\/posts\/31822\/revisions"}],"predecessor-version":[{"id":31827,"href":"https:\/\/myedme.com\/login\/wp-json\/wp\/v2\/posts\/31822\/revisions\/31827"}],"wp:attachment":[{"href":"https:\/\/myedme.com\/login\/wp-json\/wp\/v2\/media?parent=31822"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/myedme.com\/login\/wp-json\/wp\/v2\/categories?post=31822"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/myedme.com\/login\/wp-json\/wp\/v2\/tags?post=31822"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}