{"id":196219,"date":"2025-03-03T18:39:39","date_gmt":"2025-03-03T18:39:39","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=196219"},"modified":"2025-03-03T18:39:42","modified_gmt":"2025-03-03T18:39:42","slug":"a-walkway-is-4-feet-wide-and-is-paved-with-square-stones-that-are-eight-inches-wide","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/03\/03\/a-walkway-is-4-feet-wide-and-is-paved-with-square-stones-that-are-eight-inches-wide\/","title":{"rendered":"A walkway is 4 feet wide and is paved with square stones that are eight inches wide"},"content":{"rendered":"\n<p>1. A walkway is 4 feet wide and is paved with square stones that are eight inches wide. How many stones wide is the path?<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>a. 3<\/li>\n\n\n\n<li>b. 10<\/li>\n\n\n\n<li>c. 6<\/li>\n\n\n\n<li>d. 12<\/li>\n\n\n\n<li>e. 4<\/li>\n<\/ul>\n\n\n\n<p>2. At which points on the curve y = 1 + 40x<sup>3<\/sup>&nbsp;&#8211; 3x<sup>5<\/sup>&nbsp;does the tangent line have the largest slope?<\/p>\n\n\n\n<p>(x,y) Smaller x-value<\/p>\n\n\n\n<p>(x,y) Larger x-value<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\">The correct answer and explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p>Let&#8217;s solve each problem step by step.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Problem 1: Walkway Width in Stones<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The walkway is <strong>4 feet wide<\/strong>.<\/li>\n\n\n\n<li>The stones are <strong>8 inches wide<\/strong>.<\/li>\n\n\n\n<li>Convert feet to inches: 4\u00a0feet=4\u00d712=48\u00a0inches4 \\text{ feet} = 4 \\times 12 = 48 \\text{ inches}<\/li>\n\n\n\n<li>Now, determine how many stones fit into the width: 48\u00a0inches8\u00a0inches\u00a0per\u00a0stone=6\\frac{48 \\text{ inches}}{8 \\text{ inches per stone}} = 6<\/li>\n\n\n\n<li>The correct answer is <strong>(c) 6<\/strong>.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Problem 2: Finding Points with Maximum Slope<\/strong><\/h3>\n\n\n\n<p>Given the function: y=1+40&#215;3\u22123x5y = 1 + 40x^3 &#8211; 3x^5<\/p>\n\n\n\n<p>The slope of the tangent line is given by the derivative: dydx=120&#215;2\u221215&#215;4\\frac{dy}{dx} = 120x^2 &#8211; 15x^4<\/p>\n\n\n\n<p>To find the points where the tangent has the <strong>largest slope<\/strong>, we differentiate again to find critical points of dy\/dxdy\/dx: d2ydx2=240x\u221260&#215;3\\frac{d^2y}{dx^2} = 240x &#8211; 60x^3<\/p>\n\n\n\n<p>Set the second derivative equal to zero: 240x\u221260&#215;3=0240x &#8211; 60x^3 = 0<\/p>\n\n\n\n<p>Factor: 60x(4\u2212x2)=060x(4 &#8211; x^2) = 0<\/p>\n\n\n\n<p>Solve for xx: x=0orx=\u00b12x = 0 \\quad \\text{or} \\quad x = \\pm2<\/p>\n\n\n\n<p>To determine where the slope is maximum, we check d2y\/dx2d^2y\/dx^2 at these points. The largest positive value of d2y\/dx2d^2y\/dx^2 occurs at x=\u22122x = -2 and x=2x = 2, indicating maximum slopes.<\/p>\n\n\n\n<p>Find the corresponding <strong>y-values<\/strong>: y(\u22122)=1+40(\u22122)3\u22123(\u22122)5=1+40(\u22128)\u22123(\u221232)y(-2) = 1 + 40(-2)^3 &#8211; 3(-2)^5 = 1 + 40(-8) &#8211; 3(-32) =1\u2212320+96=\u2212223= 1 &#8211; 320 + 96 = -223 y(2)=1+40(2)3\u22123(2)5=1+40(8)\u22123(32)y(2) = 1 + 40(2)^3 &#8211; 3(2)^5 = 1 + 40(8) &#8211; 3(32) =1+320\u221296=225= 1 + 320 &#8211; 96 = 225<\/p>\n\n\n\n<p>Thus, the points where the tangent has the largest slope are:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Smaller x-value:<\/strong> (-2, -223)<\/li>\n\n\n\n<li><strong>Larger x-value:<\/strong> (2, 225)<\/li>\n<\/ul>\n\n\n\n<p>Now, I will generate an image of the function y=1+40&#215;3\u22123x5y = 1 + 40x^3 &#8211; 3x^5 showing the points where the maximum slope occurs.<\/p>\n\n\n\n<p>Here is the graph of the function y=1+40&#215;3\u22123x5y = 1 + 40x^3 &#8211; 3x^5, highlighting the points (\u22122,\u2212223)(-2, -223) and (2,225)(2, 225) where the tangent line has the largest slope. Let me know if you need any further explanation!<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/03\/image-129-1024x791.png\" alt=\"\" class=\"wp-image-196220\"\/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>1. A walkway is 4 feet wide and is paved with square stones that are eight inches wide. How many stones wide is the path? 2. At which points on the curve y = 1 + 40&#215;3&nbsp;&#8211; 3&#215;5&nbsp;does the tangent line have the largest slope? (x,y) Smaller x-value (x,y) Larger x-value The correct answer and [&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-196219","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/196219","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=196219"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/196219\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=196219"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=196219"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=196219"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}