{"id":190410,"date":"2025-02-12T08:43:32","date_gmt":"2025-02-12T08:43:32","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=190410"},"modified":"2025-02-12T08:43:35","modified_gmt":"2025-02-12T08:43:35","slug":"determine-whether-the-lines-l1-and-l2-are-parallel-skew-or-intersecting","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/02\/12\/determine-whether-the-lines-l1-and-l2-are-parallel-skew-or-intersecting\/","title":{"rendered":"Determine whether the lines l1 and l2 are parallel, skew, or intersecting"},"content":{"rendered":"\n<p>Determine whether the lines l1 and l2 are parallel, skew, or intersecting. If they intersect, find the point of intersection.<\/p>\n\n\n\n<p>l1: x=3-2t, y=7+4t, z=-3+8t<\/p>\n\n\n\n<p>l2: x=-1-u, y=18+3u, z=7+2u<\/p>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\"><strong>The Correct Answer and Explanation is :<\/strong><\/mark><\/p>\n\n\n\n<p>Let&#8217;s analyze the given parametric equations for lines ( l_1 ) and ( l_2 ), and determine whether they are parallel, skew, or intersecting.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Parametric Equations:<\/h3>\n\n\n\n<p>For line ( l_1 ):<br>[<br>\\begin{aligned}<br>x_1 &amp;= 3 &#8211; 2t \\<br>y_1 &amp;= 7 + 4t \\<br>z_1 &amp;= -3 + 8t<br>\\end{aligned}<br>]<br>For line ( l_2 ):<br>[<br>\\begin{aligned}<br>x_2 &amp;= -1 &#8211; u \\<br>y_2 &amp;= 18 + 3u \\<br>z_2 &amp;= 7 + 2u<br>\\end{aligned}<br>]<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 1: Direction Vectors<\/h3>\n\n\n\n<p>First, we extract the direction vectors of the lines. The direction vector of ( l_1 ) is the coefficient of the parameter ( t ) in the equations of ( l_1 ):<br>[<br>\\mathbf{d_1} = (-2, 4, 8)<br>]<br>Similarly, for ( l_2 ), the direction vector is the coefficient of ( u ) in the equations of ( l_2 ):<br>[<br>\\mathbf{d_2} = (-1, 3, 2)<br>]<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 2: Check if the Lines Are Parallel<\/h3>\n\n\n\n<p>Two lines are parallel if their direction vectors are proportional (i.e., one is a scalar multiple of the other). To check this, we compare the components of ( \\mathbf{d_1} ) and ( \\mathbf{d_2} ).<\/p>\n\n\n\n<p>[<br>\\frac{-2}{-1} = 2, \\quad \\frac{4}{3} \\neq 2, \\quad \\frac{8}{2} = 4<br>]<\/p>\n\n\n\n<p>Since the components are not proportional, the lines are <strong>not parallel<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 3: Check if the Lines Intersect<\/h3>\n\n\n\n<p>To determine if the lines intersect, we set the parametric equations of ( l_1 ) equal to the parametric equations of ( l_2 ):<\/p>\n\n\n\n<p>[<br>\\begin{aligned}<br>3 &#8211; 2t &amp;= -1 &#8211; u \\<br>7 + 4t &amp;= 18 + 3u \\<br>-3 + 8t &amp;= 7 + 2u<br>\\end{aligned}<br>]<\/p>\n\n\n\n<p>Solving this system of equations, we first rearrange them:<br>[<br>\\begin{aligned}<br>3 &#8211; 2t &amp;= -1 &#8211; u \\quad \\Rightarrow \\quad 2t &#8211; u = 4 \\<br>7 + 4t &amp;= 18 + 3u \\quad \\Rightarrow \\quad 4t &#8211; 3u = 11 \\<br>-3 + 8t &amp;= 7 + 2u \\quad \\Rightarrow \\quad 8t &#8211; 2u = 10<br>\\end{aligned}<br>]<\/p>\n\n\n\n<p>We now solve the system of equations:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>( 2t &#8211; u = 4 )<\/li>\n\n\n\n<li>( 4t &#8211; 3u = 11 )<\/li>\n\n\n\n<li>( 8t &#8211; 2u = 10 )<\/li>\n<\/ol>\n\n\n\n<p>From equation (1), solve for ( u ):<br>[<br>u = 2t &#8211; 4<br>]<\/p>\n\n\n\n<p>Substitute ( u = 2t &#8211; 4 ) into equations (2) and (3):<\/p>\n\n\n\n<p>Substitute into equation (2):<br>[<br>4t &#8211; 3(2t &#8211; 4) = 11 \\quad \\Rightarrow \\quad 4t &#8211; 6t + 12 = 11 \\quad \\Rightarrow \\quad -2t = -1 \\quad \\Rightarrow \\quad t = \\frac{1}{2}<br>]<\/p>\n\n\n\n<p>Now substitute ( t = \\frac{1}{2} ) into ( u = 2t &#8211; 4 ):<br>[<br>u = 2\\left(\\frac{1}{2}\\right) &#8211; 4 = 1 &#8211; 4 = -3<br>]<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 4: Check the Point of Intersection<\/h3>\n\n\n\n<p>Now, we check the values of ( t = \\frac{1}{2} ) and ( u = -3 ) in the parametric equations of both lines.<\/p>\n\n\n\n<p>For ( l_1 ), with ( t = \\frac{1}{2} ):<br>[<br>\\begin{aligned}<br>x_1 &amp;= 3 &#8211; 2\\left(\\frac{1}{2}\\right) = 3 &#8211; 1 = 2 \\<br>y_1 &amp;= 7 + 4\\left(\\frac{1}{2}\\right) = 7 + 2 = 9 \\<br>z_1 &amp;= -3 + 8\\left(\\frac{1}{2}\\right) = -3 + 4 = 1<br>\\end{aligned}<br>]<\/p>\n\n\n\n<p>For ( l_2 ), with ( u = -3 ):<br>[<br>\\begin{aligned}<br>x_2 &amp;= -1 &#8211; (-3) = -1 + 3 = 2 \\<br>y_2 &amp;= 18 + 3(-3) = 18 &#8211; 9 = 9 \\<br>z_2 &amp;= 7 + 2(-3) = 7 &#8211; 6 = 1<br>\\end{aligned}<br>]<\/p>\n\n\n\n<p>Since the coordinates of both lines match at ( (2, 9, 1) ), the lines <strong>intersect<\/strong> at this point.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Conclusion<\/h3>\n\n\n\n<p>The lines ( l_1 ) and ( l_2 ) are <strong>intersecting<\/strong> and the point of intersection is ( (2, 9, 1) ).<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Determine whether the lines l1 and l2 are parallel, skew, or intersecting. If they intersect, find the point of intersection. l1: x=3-2t, y=7+4t, z=-3+8t l2: x=-1-u, y=18+3u, z=7+2u The Correct Answer and Explanation is : Let&#8217;s analyze the given parametric equations for lines ( l_1 ) and ( l_2 ), and determine whether they are [&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-190410","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/190410","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=190410"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/190410\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=190410"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=190410"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=190410"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}