{"id":15356,"date":"2021-10-11T23:05:36","date_gmt":"2021-10-11T23:05:36","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/ccbcmd-math-1\/chapter\/why-it-matters-systems-of-equations-and-inequalities-2-2\/"},"modified":"2021-10-16T20:44:58","modified_gmt":"2021-10-16T20:44:58","slug":"why-it-matters-systems-of-equations-and-inequalities-2-2","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/ccbcmd-math-1\/chapter\/why-it-matters-systems-of-equations-and-inequalities-2-2\/","title":{"raw":"Why It Matters: Linear Systems","rendered":"Why It Matters: Linear Systems"},"content":{"raw":"\n<h2>Why Learn About Systems of Equations and Inequalities?<\/h2>\n[caption id=\"attachment_3935\" align=\"alignleft\" width=\"300\"]<img class=\"size-medium wp-image-3935\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/121\/2016\/08\/16002441\/Alliance_2X2_Pattern_Plane-300x225.jpeg\" alt=\"Alliance 2x2 Pattern RC Plane\" width=\"300\" height=\"225\"> An Alliance 2x2 Pattern RC Plane ready for take off.[\/caption]\n\nJoan's dad loves to build and fly model RC airplanes. One hot Saturday afternoon, Joan goes with him to fly his favorite plane. She packs them a picnic lunch and they hit the road for their favorite spot. &nbsp;On the way there, Joan's dad expresses his concern that there may be a lot of turbulence because of the hot weather and the location of the field where they will fly the plane.\n\nJoan was surprised by what her dad said. She thought turbulence only happened at high altitudes - like when you were flying in an airplane. Later, after she and her dad got home from flying his RC plane, Joan decided to Google turbulence. She was surprised to find that turbulence can happen on scales as small as gas or water passing through pipes.\n\nShe also learned that despite its occurrence in most fluid flows, such as wind, rivers, oceans, and fluids moving through pipes, scientists and mathematicians have yet to find a reliable way to model or describe its behavior with mathematics or physics. Joan was shocked; she thought math and science had answers for everything! She read further and found that the mathematical equations that are typically used to model fluid flows have&nbsp;not yet been proven to have solutions&nbsp;that always exist. Joan further found that the equations are called the Navier-Stokes equations after&nbsp;Claude-Louis Navier and&nbsp;George Gabriel Stokes.&nbsp; Early in the [latex]19th[\/latex] Century, Claude-Louis Navier in France and George Gabriel Stokes in England both derived an equation that can explain and predict the flow of fluids. The Navier-Stokes equations are a system of equations used to describe the velocity of a fluid as it moves through three-dimensional space over a specific interval of time.&nbsp;The Navier-Stokes equations are a system of three equations that contain many variables used to describe features of the fluid including temperature, speed, and density.\n\n[caption id=\"attachment_4356\" align=\"aligncenter\" width=\"268\"]<img class=\"wp-image-4356\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/117\/2016\/05\/25135654\/Ggstokes-221x300.jpg\" alt=\"Sir George Gabriel Stokes\" width=\"268\" height=\"365\"> Sir George Gabriel Stokes[\/caption]\n\n<span style=\"font-size: 1rem; text-align: initial;\">Joan found that physicists and mathematicians use the Navier\u2013Stokes equations to model the weather, ocean currents, flow of water through a pipe, and air flow around a wing. Engineers and scientists use them to design aircraft and cars, study blood flow, design power stations, and&nbsp;even understand how pollution spreads.<\/span>\n\nSurprisingly,&nbsp;our understanding of solutions to the Navier-Stokes equations remains minimal, given the&nbsp;equations'&nbsp;wide range of practical uses.&nbsp; It has not yet been proven that solutions <em>always<\/em> exist in three dimensions. The Clay Mathematics Institute has called this one of the seven most important open problems in mathematics and has offered a US [latex]$1,000,000[\/latex] prize for a solution or a counter-example.\n\nThe following week, in her algebra class, Joan learned about systems of linear equations and how to graph them and find solutions for them. Even though her classmates were surprised to find that some systems do not have solutions, Joan already knew about a famous system of equations that does not have any known solutions.\n\nHer teacher was very impressed when she shared what she had learned by spending an afternoon with her father flying RC airplanes.\n\nIn this section, we will learn how to graph systems of equations in two and three dimensions and find whether solutions exist. We will also see how systems of equations can be used to solve problems where we have two or three unknown variables.\n<h2>Contribute!<\/h2><div style=\"margin-bottom: 8px;\">Did you have an idea for improving this content? We\u2019d love your input.<\/div><a href=\"https:\/\/docs.google.com\/document\/d\/14Qg5hwyXMpF5g56MUTllB7qSts9KKCFdVHDJLr-_b1A\" target=\"_blank\" style=\"font-size: 10pt; font-weight: 600; color: #077fab; text-decoration: none; border: 2px solid #077fab; border-radius: 7px; padding: 5px 25px; text-align: center; cursor: pointer; line-height: 1.5em;\">Improve this page<\/a><a style=\"margin-left: 16px;\" target=\"_blank\" href=\"https:\/\/docs.google.com\/document\/d\/1vy-T6DtTF-BbMfpVEI7VP_R7w2A4anzYZLXR8Pk4Fu4\">Learn More<\/a>\n","rendered":"<h2>Why Learn About Systems of Equations and Inequalities?<\/h2>\n<div id=\"attachment_3935\" style=\"width: 310px\" class=\"wp-caption alignleft\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-3935\" class=\"size-medium wp-image-3935\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/121\/2016\/08\/16002441\/Alliance_2X2_Pattern_Plane-300x225.jpeg\" alt=\"Alliance 2x2 Pattern RC Plane\" width=\"300\" height=\"225\" \/><\/p>\n<p id=\"caption-attachment-3935\" class=\"wp-caption-text\">An Alliance 2&#215;2 Pattern RC Plane ready for take off.<\/p>\n<\/div>\n<p>Joan&#8217;s dad loves to build and fly model RC airplanes. One hot Saturday afternoon, Joan goes with him to fly his favorite plane. She packs them a picnic lunch and they hit the road for their favorite spot. &nbsp;On the way there, Joan&#8217;s dad expresses his concern that there may be a lot of turbulence because of the hot weather and the location of the field where they will fly the plane.<\/p>\n<p>Joan was surprised by what her dad said. She thought turbulence only happened at high altitudes &#8211; like when you were flying in an airplane. Later, after she and her dad got home from flying his RC plane, Joan decided to Google turbulence. She was surprised to find that turbulence can happen on scales as small as gas or water passing through pipes.<\/p>\n<p>She also learned that despite its occurrence in most fluid flows, such as wind, rivers, oceans, and fluids moving through pipes, scientists and mathematicians have yet to find a reliable way to model or describe its behavior with mathematics or physics. Joan was shocked; she thought math and science had answers for everything! She read further and found that the mathematical equations that are typically used to model fluid flows have&nbsp;not yet been proven to have solutions&nbsp;that always exist. Joan further found that the equations are called the Navier-Stokes equations after&nbsp;Claude-Louis Navier and&nbsp;George Gabriel Stokes.&nbsp; Early in the [latex]19th[\/latex] Century, Claude-Louis Navier in France and George Gabriel Stokes in England both derived an equation that can explain and predict the flow of fluids. The Navier-Stokes equations are a system of equations used to describe the velocity of a fluid as it moves through three-dimensional space over a specific interval of time.&nbsp;The Navier-Stokes equations are a system of three equations that contain many variables used to describe features of the fluid including temperature, speed, and density.<\/p>\n<div id=\"attachment_4356\" style=\"width: 278px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-4356\" class=\"wp-image-4356\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/117\/2016\/05\/25135654\/Ggstokes-221x300.jpg\" alt=\"Sir George Gabriel Stokes\" width=\"268\" height=\"365\" \/><\/p>\n<p id=\"caption-attachment-4356\" class=\"wp-caption-text\">Sir George Gabriel Stokes<\/p>\n<\/div>\n<p><span style=\"font-size: 1rem; text-align: initial;\">Joan found that physicists and mathematicians use the Navier\u2013Stokes equations to model the weather, ocean currents, flow of water through a pipe, and air flow around a wing. Engineers and scientists use them to design aircraft and cars, study blood flow, design power stations, and&nbsp;even understand how pollution spreads.<\/span><\/p>\n<p>Surprisingly,&nbsp;our understanding of solutions to the Navier-Stokes equations remains minimal, given the&nbsp;equations&#8217;&nbsp;wide range of practical uses.&nbsp; It has not yet been proven that solutions <em>always<\/em> exist in three dimensions. The Clay Mathematics Institute has called this one of the seven most important open problems in mathematics and has offered a US [latex]$1,000,000[\/latex] prize for a solution or a counter-example.<\/p>\n<p>The following week, in her algebra class, Joan learned about systems of linear equations and how to graph them and find solutions for them. Even though her classmates were surprised to find that some systems do not have solutions, Joan already knew about a famous system of equations that does not have any known solutions.<\/p>\n<p>Her teacher was very impressed when she shared what she had learned by spending an afternoon with her father flying RC airplanes.<\/p>\n<p>In this section, we will learn how to graph systems of equations in two and three dimensions and find whether solutions exist. We will also see how systems of equations can be used to solve problems where we have two or three unknown variables.<\/p>\n<h2>Contribute!<\/h2>\n<div style=\"margin-bottom: 8px;\">Did you have an idea for improving this content? We\u2019d love your input.<\/div>\n<p><a href=\"https:\/\/docs.google.com\/document\/d\/14Qg5hwyXMpF5g56MUTllB7qSts9KKCFdVHDJLr-_b1A\" target=\"_blank\" style=\"font-size: 10pt; font-weight: 600; color: #077fab; text-decoration: none; border: 2px solid #077fab; border-radius: 7px; padding: 5px 25px; text-align: center; cursor: pointer; line-height: 1.5em;\">Improve this page<\/a><a style=\"margin-left: 16px;\" target=\"_blank\" href=\"https:\/\/docs.google.com\/document\/d\/1vy-T6DtTF-BbMfpVEI7VP_R7w2A4anzYZLXR8Pk4Fu4\">Learn More<\/a><\/p>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-15356\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Original<\/div><ul class=\"citation-list\"><li>Revision and Adaptation. <strong>Provided by<\/strong>: Lumen Learning. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Navieru2013Stokes equations. <strong>Provided by<\/strong>: Wikipedia. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/en.wikipedia.org\/wiki\/Navier%E2%80%93Stokes_equations\">https:\/\/en.wikipedia.org\/wiki\/Navier%E2%80%93Stokes_equations<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><li>Sir George Gabriel Stokes (13 August 1819u20131 February 1903). <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File%3AGgstokes.jpg\">https:\/\/commons.wikimedia.org\/wiki\/File%3AGgstokes.jpg<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/about\/pdm\">Public Domain: No Known Copyright<\/a><\/em><\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">Public domain content<\/div><ul class=\"citation-list\"><li>Navier-Stokes Equation. <strong>Provided by<\/strong>: Clay Mathematics Institute. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/www.claymath.org\/millennium-problems\/navier%E2%80%93stokes-equation\">http:\/\/www.claymath.org\/millennium-problems\/navier%E2%80%93stokes-equation<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/about\/pdm\">Public Domain: No Known Copyright<\/a><\/em><\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":167848,"menu_order":1,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Navieru2013Stokes 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