{"id":219790,"date":"2025-05-26T20:08:16","date_gmt":"2025-05-26T20:08:16","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=219790"},"modified":"2025-05-26T20:08:18","modified_gmt":"2025-05-26T20:08:18","slug":"match-each-function-name-with-its-equation-3","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/26\/match-each-function-name-with-its-equation-3\/","title":{"rendered":"Match each function name with its equation."},"content":{"rendered":"\n<p>Match each function name with its equation.<\/p>\n\n\n\n<p>Find a linear differential operator that annihilates the given function. (Use D for the differential operator.)<\/p>\n\n\n\n<p>For, 1+6x &#8211; 2&#215;3 and, e-x + 2xex &#8211; x2ex<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-1-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p>To <strong>find a linear differential operator<\/strong> that <em>annihilates<\/em> a given function means to find a differential operator L(D)L(D), written in terms of D=ddxD = \\frac{d}{dx}, such that: L(D)[f(x)]=0L(D)[f(x)] = 0<\/p>\n\n\n\n<p>We are given two separate functions to analyze:<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Function 1: f(x)=1+6x\u22122x3f(x) = 1 + 6x &#8211; 2x^3<\/strong><\/h3>\n\n\n\n<p>This is a <strong>polynomial function<\/strong> of degree 3.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Step 1: Recall the rule<\/h4>\n\n\n\n<p>Any polynomial of degree nn is annihilated by the differential operator Dn+1D^{n+1}. So, for a polynomial of degree 3: D4[1+6x\u22122&#215;3]=0D^4[1 + 6x &#8211; 2x^3] = 0<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u2705 <strong>Answer:<\/strong><\/h4>\n\n\n\n<p>The linear differential operator that annihilates this function is: D4\\boxed{D^4}<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Function 2: f(x)=e\u2212x+2xex\u2212x2exf(x) = e^{-x} + 2x e^x &#8211; x^2 e^x<\/strong><\/h3>\n\n\n\n<p>This is a <strong>linear combination<\/strong> of exponential and exponential-polynomial terms. Let&#8217;s break it down:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>e\u2212xe^{-x}: Annihilated by (D+1)(D + 1)<\/li>\n\n\n\n<li>2xex2x e^x: Annihilated by (D\u22121)2(D &#8211; 1)^2<\/li>\n\n\n\n<li>\u2212x2ex-x^2 e^x: Annihilated by (D\u22121)3(D &#8211; 1)^3<\/li>\n<\/ul>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>In general, xneaxx^n e^{ax} is annihilated by (D\u2212a)n+1(D &#8211; a)^{n+1}<\/p>\n<\/blockquote>\n\n\n\n<p>So, we take the <strong>least common multiple (LCM)<\/strong> of all individual annihilators:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>(D+1)(D + 1) from e\u2212xe^{-x}<\/li>\n\n\n\n<li>(D\u22121)3(D &#8211; 1)^3 from 2xex2x e^x and \u2212x2ex-x^2 e^x<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\">\u2705 <strong>Answer:<\/strong><\/h4>\n\n\n\n<p>The full differential operator is: (D+1)(D\u22121)3\\boxed{(D + 1)(D &#8211; 1)^3}<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 Final Answers:<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li>For 1+6x\u22122&#215;31 + 6x &#8211; 2x^3:\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003<\/li>\n<\/ol>\n\n\n\n<p>D4\\boxed{D^4}<\/p>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li>For e\u2212x+2xex\u2212x2exe^{-x} + 2x e^x &#8211; x^2 e^x:\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003\u2003<\/li>\n<\/ol>\n\n\n\n<p>(D+1)(D\u22121)3\\boxed{(D + 1)(D &#8211; 1)^3}<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u270d\ufe0f Explanation <\/h3>\n\n\n\n<p>In differential equations, a <strong>linear differential operator<\/strong> like D=ddxD = \\frac{d}{dx} acts on a function to produce its derivative. An operator <strong>annihilates<\/strong> a function when applying it results in zero. To find such an operator, we look at the structure of the function.<\/p>\n\n\n\n<p>For the first function, 1+6x\u22122&#215;31 + 6x &#8211; 2x^3, it\u2019s a polynomial of degree 3. Each differentiation reduces the degree by 1. After four derivatives, the result is zero. Hence, D4D^4 is the smallest differential operator that annihilates it.<\/p>\n\n\n\n<p>For the second function, e\u2212x+2xex\u2212x2exe^{-x} + 2x e^x &#8211; x^2 e^x, each term is exponential or exponential times a polynomial. The term e\u2212xe^{-x} is annihilated by D+1D + 1 because the derivative of e\u2212xe^{-x} is \u2212e\u2212x-e^{-x}. The terms 2xex2x e^x and \u2212x2ex-x^2 e^x are of the form xnexx^n e^x, which are annihilated by (D\u22121)n+1(D &#8211; 1)^{n+1}. Specifically, xexx e^x is annihilated by (D\u22121)2(D &#8211; 1)^2, and x2exx^2 e^x by (D\u22121)3(D &#8211; 1)^3.<\/p>\n\n\n\n<p>To annihilate the whole function, we need a common operator that eliminates all terms. That means we need to take the product of their annihilators: (D+1)(D + 1) and (D\u22121)3(D &#8211; 1)^3. This product ensures that each term individually is sent to zero.<\/p>\n\n\n\n<p>Therefore, the second function is annihilated by (D+1)(D\u22121)3(D + 1)(D &#8211; 1)^3.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/05\/learnexams-banner7-30.jpeg\" alt=\"\" class=\"wp-image-219792\"\/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Match each function name with its equation. Find a linear differential operator that annihilates the given function. (Use D for the differential operator.) For, 1+6x &#8211; 2&#215;3 and, e-x + 2xex &#8211; x2ex The Correct Answer and Explanation is: To find a linear differential operator that annihilates a given function means to find a differential [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-219790","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/219790","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=219790"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/219790\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=219790"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=219790"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=219790"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}