{"id":377,"date":"2019-06-26T23:49:13","date_gmt":"2019-06-26T23:49:13","guid":{"rendered":"http:\/\/funfacts.104.42.120.246.xip.io\/?page_id=377"},"modified":"2019-11-22T19:47:31","modified_gmt":"2019-11-22T19:47:31","slug":"gamma-function","status":"publish","type":"page","link":"https:\/\/math.hmc.edu\/funfacts\/gamma-function\/","title":{"rendered":"Gamma Function"},"content":{"rendered":"\n<p style=\"text-align:left\">The Gamma function is an amazing integral:&nbsp;<\/p>\n\n\n\n<p style=\"text-align:center\">Gamma(x) = INTEGRAL<sub>t=0 to infinity<\/sub>&nbsp;t<sup>x-1<\/sup><em>e<\/em><sup>-t<\/sup>&nbsp;dt .<\/p>\n\n\n\n<p>Using integration by parts, you can show that this function satisfies the property<\/p>\n\n\n\n<p style=\"text-align:center\">Gamma(x) = (x-1) Gamma(x-1).<\/p>\n\n\n\n<p>Using Gamma(1)=1, you can calculate Gamma(2), Gamma(3),&#8230;&nbsp;<br>Does this remind you of anything?<\/p>\n\n\n\n<p>Surprise: the Gamma function satisfies Gamma(n) = Factorial(n-1).&nbsp;<br>(I would have used the notation &#8220;!&#8221; but you might think I was just excited!)<\/p>\n\n\n\n<p>So you can think of the Gamma function as being a continuous form of the\u00a0factorial\u00a0function. It satisfies lots of cool properties; here is just one:\u00a0<\/p>\n\n\n\n<p style=\"text-align:center\">Gamma(1\/2) = Sqrt[Pi].<\/p>\n\n\n\n<p><strong>Presentation&nbsp;Suggestions:<\/strong><br>Calculus&nbsp;students might be challenged to compute Gamma(2), Gamma(3), etc. and discover the connection with the factorial function. You may wish to assign the integration by parts as a homework exercise prior to presenting this Fun Fact.<\/p>\n\n\n\n<p><strong>The&nbsp;Math&nbsp;Behind&nbsp;the&nbsp;Fact:<\/strong><br>The Gamma function is an important function in analysis,&nbsp;complex analysis,&nbsp;combinatorics, and&nbsp;probability.<\/p>\n\n\n\n<p><strong>How to Cite this Page:<\/strong>&nbsp;<br>Su, Francis E., et al. &#8220;Gamma Function.&#8221;&nbsp;<em>Math Fun Facts<\/em>. &lt;http:\/\/www.math.hmc.edu\/funfacts&gt;.<\/p>\n\n\n\n<p><strong>Fun Fact suggested by:   <\/strong><br>Michael Moody <\/p>\n","protected":false},"excerpt":{"rendered":"<p>The Gamma function is an amazing integral:&nbsp; Gamma(x) = INTEGRALt=0 to infinity&nbsp;tx-1e-t&nbsp;dt . Using integration by parts, you can show&#46;&#46;&#46;<\/p>\n","protected":false},"author":7,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"tags":[20,7,115,4],"class_list":["post-377","page","type-page","status-publish","hentry","tag-analysis","tag-calculus","tag-continuous-factorial","tag-medium"],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/pages\/377","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/comments?post=377"}],"version-history":[{"count":4,"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/pages\/377\/revisions"}],"predecessor-version":[{"id":1458,"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/pages\/377\/revisions\/1458"}],"wp:attachment":[{"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/media?parent=377"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/math.hmc.edu\/funfacts\/wp-json\/wp\/v2\/tags?post=377"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}