{"id":7942,"date":"2023-05-03T22:36:46","date_gmt":"2023-05-03T17:06:46","guid":{"rendered":"https:\/\/physicscatalyst.com\/article\/?p=7942"},"modified":"2023-04-30T23:18:04","modified_gmt":"2023-04-30T17:48:04","slug":"how-to-prove-a-function-is-one-to-one-graphically","status":"publish","type":"post","link":"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/","title":{"rendered":"how to prove a function is one-to-one graphically"},"content":{"rendered":"\n<p>In this post, we will checking how to prove a function is one-to-one graphically .Examples and Problems are also given to help the student. This will also answer the question How do you know if the function is one-one<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">how to prove a function is one-to-one graphically<\/h2>\n\n\n\n<p>We can prove using Horizontal line test.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What is horizontal line test<\/h2>\n\n\n\n<p>A function is one one if, and only if, for all elements a<sub>1<\/sub>\u00a0and a<sub>2<\/sub>\u00a0in A,<br>if f(a<sub>1<\/sub>) = f(a<sub>2<\/sub>), then a<sub>1<\/sub>\u00a0= a<sub>2<\/sub> <\/p>\n\n\n\n<p>On the graph, two points will lie in the same horizontal  line if and only if the second coordinate of the two points is the same. i,e we have the condition where<\/p>\n\n\n\n<p>f(a<sub>1<\/sub>) = f(a<sub>2<\/sub>) and a<sub>1<\/sub>\u00a0is not equal to  a<sub>2<\/sub><\/p>\n\n\n\n<p>Therefore if a horizontal  line intersects the  graph at two points then it is not an one-one  function. This is called the <strong>Horizontal line test<\/strong>. If all horizontal  lines intersect a curve at most once then the curve represents a one-one  function.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">How to use the it<\/h2>\n\n\n\n<p>To use it, take a rule or other straight edge and draw a line parallel to the x-axis for any chosen value of y. If the horizontal  line you drew intersects the graph more than once for any value of y then the graph is not the graph of a one-one function. If alternatively, a horizontal line intersects the graph no more than once, no matter where the horizontal  line is placed, then the graph is the graph of a one one function. <\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Examples<\/h2>\n\n\n\n<p>(a)  $f(x) = x^2$<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-1.png\"><img loading=\"lazy\" decoding=\"async\" width=\"310\" height=\"354\" src=\"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-1.png\" alt=\"\" class=\"wp-image-7943\" srcset=\"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-1.png 310w, https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-1-263x300.png 263w\" sizes=\"auto, (max-width: 310px) 100vw, 310px\" \/><\/a><\/figure>\n\n\n\n<p>Clearly this is not one-one function<\/p>\n\n\n\n<p>(b) $f(x) = x+3$<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-2.png\"><img loading=\"lazy\" decoding=\"async\" width=\"370\" height=\"392\" src=\"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-2.png\" alt=\"\" class=\"wp-image-7944\" srcset=\"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-2.png 370w, https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-2-283x300.png 283w\" sizes=\"auto, (max-width: 370px) 100vw, 370px\" \/><\/a><\/figure>\n\n\n\n<p>Clearly this is one-one<\/p>\n\n\n\n<p>(c) $f(x) = x|x|$<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-3.png\"><img loading=\"lazy\" decoding=\"async\" width=\"425\" height=\"436\" src=\"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-3.png\" alt=\"\" class=\"wp-image-7945\" srcset=\"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-3.png 425w, https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-3-292x300.png 292w\" sizes=\"auto, (max-width: 425px) 100vw, 425px\" \/><\/a><\/figure>\n\n\n\n<p>Clearly this is one-one<\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>In this post, we will checking how to prove a function is one-to-one graphically .Examples and Problems are also given to help the student. This will also answer the question How do you know if the function is one-one how to prove a function is one-to-one graphically We can prove using Horizontal line test. What [&hellip;]<\/p>\n","protected":false},"author":8,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_uag_custom_page_level_css":"","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":"","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":[498],"tags":[],"class_list":["post-7942","post","type-post","status-publish","format-standard","hentry","category-maths"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.4 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>how to prove a function is one-to-one graphically - physicscatalyst&#039;s Blog<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"how to prove a function is one-to-one graphically - physicscatalyst&#039;s Blog\" \/>\n<meta property=\"og:description\" content=\"In this post, we will checking how to prove a function is one-to-one graphically .Examples and Problems are also given to help the student. This will also answer the question How do you know if the function is one-one how to prove a function is one-to-one graphically We can prove using Horizontal line test. What [&hellip;]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/\" \/>\n<meta property=\"og:site_name\" content=\"physicscatalyst&#039;s Blog\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/PhysicsCatalyst\" \/>\n<meta property=\"article:author\" content=\"https:\/\/www.facebook.com\/PhysicsCatalyst\" \/>\n<meta property=\"article:published_time\" content=\"2023-05-03T17:06:46+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-1.png\" \/>\n<meta name=\"author\" content=\"physicscatalyst\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"physicscatalyst\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"2 minutes\" \/>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"how to prove a function is one-to-one graphically - physicscatalyst&#039;s Blog","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/","og_locale":"en_US","og_type":"article","og_title":"how to prove a function is one-to-one graphically - physicscatalyst&#039;s Blog","og_description":"In this post, we will checking how to prove a function is one-to-one graphically .Examples and Problems are also given to help the student. This will also answer the question How do you know if the function is one-one how to prove a function is one-to-one graphically We can prove using Horizontal line test. What [&hellip;]","og_url":"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/","og_site_name":"physicscatalyst&#039;s Blog","article_publisher":"https:\/\/www.facebook.com\/PhysicsCatalyst","article_author":"https:\/\/www.facebook.com\/PhysicsCatalyst","article_published_time":"2023-05-03T17:06:46+00:00","og_image":[{"url":"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-1.png","type":"","width":"","height":""}],"author":"physicscatalyst","twitter_misc":{"Written by":"physicscatalyst","Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/#article","isPartOf":{"@id":"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/"},"author":{"name":"physicscatalyst","@id":"https:\/\/physicscatalyst.com\/article\/#\/schema\/person\/9b302efdc9b32e459cb1e61ab7506d3f"},"headline":"how to prove a function is one-to-one graphically","datePublished":"2023-05-03T17:06:46+00:00","mainEntityOfPage":{"@id":"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/"},"wordCount":294,"commentCount":0,"publisher":{"@id":"https:\/\/physicscatalyst.com\/article\/#organization"},"image":{"@id":"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/#primaryimage"},"thumbnailUrl":"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-1.png","articleSection":["Maths"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/","url":"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/","name":"how to prove a function is one-to-one graphically - physicscatalyst&#039;s Blog","isPartOf":{"@id":"https:\/\/physicscatalyst.com\/article\/#website"},"primaryImageOfPage":{"@id":"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/#primaryimage"},"image":{"@id":"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/#primaryimage"},"thumbnailUrl":"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-1.png","datePublished":"2023-05-03T17:06:46+00:00","breadcrumb":{"@id":"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/#primaryimage","url":"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-1.png","contentUrl":"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2023\/04\/horizontal-line-test-fig-1.png"},{"@type":"BreadcrumbList","@id":"https:\/\/physicscatalyst.com\/article\/how-to-prove-a-function-is-one-to-one-graphically\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/physicscatalyst.com\/article\/"},{"@type":"ListItem","position":2,"name":"Maths","item":"https:\/\/physicscatalyst.com\/article\/maths\/"},{"@type":"ListItem","position":3,"name":"how to prove a function is one-to-one graphically"}]},{"@type":"WebSite","@id":"https:\/\/physicscatalyst.com\/article\/#website","url":"https:\/\/physicscatalyst.com\/article\/","name":"physicscatalyst's Blog","description":"Learn free for class 9th, 10th science\/maths , 12th and IIT-JEE Physics and maths.","publisher":{"@id":"https:\/\/physicscatalyst.com\/article\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/physicscatalyst.com\/article\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/physicscatalyst.com\/article\/#organization","name":"physicscatalyst","url":"https:\/\/physicscatalyst.com\/article\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/physicscatalyst.com\/article\/#\/schema\/logo\/image\/","url":"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2024\/08\/cropped-logo-1.jpg","contentUrl":"https:\/\/physicscatalyst.com\/article\/wp-content\/uploads\/2024\/08\/cropped-logo-1.jpg","width":96,"height":96,"caption":"physicscatalyst"},"image":{"@id":"https:\/\/physicscatalyst.com\/article\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/PhysicsCatalyst","https:\/\/x.com\/physicscatalyst","https:\/\/www.youtube.com\/user\/thephysicscatalyst","https:\/\/www.instagram.com\/physicscatalyst\/"]},{"@type":"Person","@id":"https:\/\/physicscatalyst.com\/article\/#\/schema\/person\/9b302efdc9b32e459cb1e61ab7506d3f","name":"physicscatalyst","sameAs":["https:\/\/physicscatalyst.com","https:\/\/www.facebook.com\/PhysicsCatalyst","https:\/\/x.com\/physicscatalyst"]}]}},"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false,"shareaholic-thumbnail":false},"uagb_author_info":{"display_name":"physicscatalyst","author_link":"https:\/\/physicscatalyst.com\/article\/author\/physicscatalyst\/"},"uagb_comment_info":0,"uagb_excerpt":"In this post, we will checking how to prove a function is one-to-one graphically .Examples and Problems are also given to help the student. This will also answer the question How do you know if the function is one-one how to prove a function is one-to-one graphically We can prove using Horizontal line test. What&hellip;","_links":{"self":[{"href":"https:\/\/physicscatalyst.com\/article\/wp-json\/wp\/v2\/posts\/7942","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/physicscatalyst.com\/article\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/physicscatalyst.com\/article\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/physicscatalyst.com\/article\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/physicscatalyst.com\/article\/wp-json\/wp\/v2\/comments?post=7942"}],"version-history":[{"count":1,"href":"https:\/\/physicscatalyst.com\/article\/wp-json\/wp\/v2\/posts\/7942\/revisions"}],"predecessor-version":[{"id":7946,"href":"https:\/\/physicscatalyst.com\/article\/wp-json\/wp\/v2\/posts\/7942\/revisions\/7946"}],"wp:attachment":[{"href":"https:\/\/physicscatalyst.com\/article\/wp-json\/wp\/v2\/media?parent=7942"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/physicscatalyst.com\/article\/wp-json\/wp\/v2\/categories?post=7942"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/physicscatalyst.com\/article\/wp-json\/wp\/v2\/tags?post=7942"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}