{"id":1585,"date":"2017-11-29T19:24:26","date_gmt":"2017-11-30T00:24:26","guid":{"rendered":"http:\/\/blog.richmond.edu\/math320\/?p=1585"},"modified":"2017-12-06T12:33:49","modified_gmt":"2017-12-06T17:33:49","slug":"daily-definition-1128","status":"publish","type":"post","link":"https:\/\/blog.richmond.edu\/math320\/2017\/11\/29\/daily-definition-1128\/","title":{"rendered":"Daily Definition (11\/28)"},"content":{"rendered":"<p>The problem from the proof outline from 11\/28 covered the definition of a nondecreasing function. We learned about the nondecreasing sequences but not nondecreasing functions in this course. In this post, I would like to review the definition of a non-decreasing function and further explore relative definitions of a nonincreasing function, an increasing function, a decreasing function.<\/p>\n<p>Nondecreasing function: A function f(x) is said to be nondecreasing on an interval I if <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=f%28b%29+%5Cgeq+f%28a%29&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"f(b) &#92;geq f(a)\" class=\"latex\" \/> for all\u00a0b&gt;a, where <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=a%2Cb%5Cin+I&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"a,b&#92;in I\" class=\"latex\" \/><\/p>\n<p>Nonincreasing function: a function f(x) is said to be nonincreasing on an\u00a0interval\u00a0I\u00a0if <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=f%28b%29+%5Cleq+f%28a%29&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"f(b) &#92;leq f(a)\" class=\"latex\" \/> for all b&gt;a with\u00a0<img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=a%2Cb%5Cin+I&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"a,b&#92;in I\" class=\"latex\" \/>.<\/p>\n<p>Increasing function:A function\u00a0f(x) increases on an\u00a0interval\u00a0I\u00a0if <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=f%28b%29+%5Cgeq+f%28a%29&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"f(b) &#92;geq f(a)\" class=\"latex\" \/> for all\u00a0b&gt;a, where\u00a0<img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=a%2Cb%5Cin+I&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"a,b&#92;in I\" class=\"latex\" \/>. If\u00a0,\u00a0f(b)&gt;f(a), for all\u00a0b&gt;a, the function is said to be\u00a0strictly increasing.<\/p>\n<p>Decreasing function: a function\u00a0f(x) decreases on an\u00a0interval\u00a0I\u00a0if <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=f%28b%29+%5Cleq+f%28a%29&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"f(b) &#92;leq f(a)\" class=\"latex\" \/> for all\u00a0b&gt;a\u00a0with\u00a0<img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=a%2Cb%5Cin+I&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"a,b&#92;in I\" class=\"latex\" \/>. If\u00a0f(b)&lt;f(a), for all\u00a0b&gt;a, the function is said to be\u00a0strictly decreasing.<\/p>\n<p>&nbsp;<\/p>\n<p>Further thoughts:<\/p>\n<p>If the\u00a0derivative\u00a0f'(x) of a\u00a0continuous function\u00a0f(x)\u00a0satisfies ,f'(x)&gt;0 on an\u00a0open interval (a,b), then f(x) is increasing on (a,b). However, a function may increase on an interval without having a derivative defined at all points. For example, the function <img decoding=\"async\" src=\"https:\/\/s0.wp.com\/latex.php?latex=x%5E%5Cfrac%7B1%7D%7B3%7D&#038;bg=ffffff&#038;fg=000&#038;s=0&#038;c=20201002\" alt=\"x^&#92;frac{1}{3}\" class=\"latex\" \/> (see the graph below)is increasing everywhere, including the origin\u00a0x=0, despite the fact that the\u00a0derivative\u00a0is not defined at that point.<\/p>\n<p><a href=\"https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-19.20.38.png?ssl=1\"><br \/>\n<img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"1594\" data-permalink=\"https:\/\/blog.richmond.edu\/math320\/2017\/11\/29\/daily-definition-1128\/screen-shot-2017-11-29-at-19-20-38\/\" data-orig-file=\"https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-19.20.38.png?fit=1210%2C682&amp;ssl=1\" data-orig-size=\"1210,682\" data-comments-opened=\"0\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"Screen Shot 2017-11-29 at 19.20.38\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-19.20.38.png?fit=300%2C169&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-19.20.38.png?fit=600%2C338&amp;ssl=1\" class=\"size-medium wp-image-1594 aligncenter\" src=\"https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-19.20.38-300x169.png?resize=300%2C169&#038;ssl=1\" alt=\"\" width=\"300\" height=\"169\" srcset=\"https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-19.20.38.png?resize=300%2C169&amp;ssl=1 300w, https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-19.20.38.png?resize=768%2C433&amp;ssl=1 768w, https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-19.20.38.png?resize=1024%2C577&amp;ssl=1 1024w, https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-19.20.38.png?w=1210&amp;ssl=1 1210w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>This graph also demonstrates the features of nondecreasing functions, nonincreasing functions, increasing functions and decreasing functions.<\/p>\n<p><a href=\"https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-12.31.17.png?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"1586\" data-permalink=\"https:\/\/blog.richmond.edu\/math320\/2017\/11\/29\/daily-definition-1128\/screen-shot-2017-11-29-at-12-31-17\/\" data-orig-file=\"https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-12.31.17.png?fit=648%2C316&amp;ssl=1\" data-orig-size=\"648,316\" data-comments-opened=\"0\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"Screen Shot 2017-11-29 at 12.31.17\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-12.31.17.png?fit=300%2C146&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-12.31.17.png?fit=600%2C293&amp;ssl=1\" class=\"size-medium wp-image-1586 aligncenter\" src=\"https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-12.31.17-300x146.png?resize=300%2C146&#038;ssl=1\" alt=\"\" width=\"300\" height=\"146\" srcset=\"https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-12.31.17.png?resize=300%2C146&amp;ssl=1 300w, https:\/\/i0.wp.com\/blog.richmond.edu\/math320\/files\/2017\/11\/Screen-Shot-2017-11-29-at-12.31.17.png?w=648&amp;ssl=1 648w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>Reference:<\/p>\n<p>Jeffreys, H. and Jeffreys, B.\u00a0S. &#8220;Increasing and Decreasing Functions.&#8221; \u00a71.065 in\u00a0<i>Methods of Mathematical Physics, 3rd ed.<\/i>\u00a0Cambridge, England: Cambridge University Press, p.\u00a022, 1988.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The problem from the proof outline from 11\/28 covered the definition of a nondecreasing function. We learned about the nondecreasing sequences but not nondecreasing functions in this course. In this post, I would like to review the definition of a non-decreasing function and further explore relative definitions of a nonincreasing function, an increasing function, a [&hellip;]<\/p>\n","protected":false},"author":2107,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[58820,58823],"tags":[],"class_list":["post-1585","post","type-post","status-publish","format-standard","hentry","category-daily-blogs","category-definitions"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p7L4E1-pz","jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/blog.richmond.edu\/math320\/wp-json\/wp\/v2\/posts\/1585","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.richmond.edu\/math320\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.richmond.edu\/math320\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.richmond.edu\/math320\/wp-json\/wp\/v2\/users\/2107"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.richmond.edu\/math320\/wp-json\/wp\/v2\/comments?post=1585"}],"version-history":[{"count":0,"href":"https:\/\/blog.richmond.edu\/math320\/wp-json\/wp\/v2\/posts\/1585\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.richmond.edu\/math320\/wp-json\/wp\/v2\/media?parent=1585"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.richmond.edu\/math320\/wp-json\/wp\/v2\/categories?post=1585"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.richmond.edu\/math320\/wp-json\/wp\/v2\/tags?post=1585"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}