document.write( "Question 1197954: What is the angle Θ between the two vectors u=<3,4> and v<2,1> \n" ); document.write( "
Algebra.Com's Answer #831449 by MathLover1(20850)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "What is the angle \"theta\" between the two vectors \"u\"=<\"3\",\"4\"> and \"v\"<\"2\",\"1\">\r
\n" ); document.write( "\n" ); document.write( "The angle \"theta\" between two vectors \"u+\"and \"v\" is related to the modulus (or magnitude) and scaler (or dot) product of \"u+\"and \"v\" by the relationship:\r
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\n" ); document.write( "\n" ); document.write( "\"u%2Av=+abs%28u%29%2Aabs%28v%29%2Acos%28theta%29\"\r
\n" ); document.write( "\n" ); document.write( "first find dot product:
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\n" ); document.write( "\"u%2Av\"=<\"3\",\"4\">*<\"2\",\"1\">\r
\n" ); document.write( "\n" ); document.write( "\"u%2Av=3%2A2+%2B4%2A1\"\r
\n" ); document.write( "\n" ); document.write( "\"u%2Av=10\"\r
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\n" ); document.write( "\n" ); document.write( "now find the modulus: \r
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\n" ); document.write( "\n" ); document.write( "\"abs%28u%29=sqrt%283%5E2%2B4%5E2%29=sqrt%2825%29=5\"\r
\n" ); document.write( "\n" ); document.write( "\"abs%28v%29=sqrt%282%5E2%2B1%5E2%29=sqrt%285%29\"\r
\n" ); document.write( "\n" ); document.write( "their product:\r
\n" ); document.write( "\n" ); document.write( "\"abs%28u%29%2Aabs%28v%29=5sqrt%285%29\"\r
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\n" ); document.write( "\n" ); document.write( "plug all in formula above:\r
\n" ); document.write( "\n" ); document.write( "\"10=+5sqrt%285%29%2Acos%28theta%29\"\r
\n" ); document.write( "\n" ); document.write( "\"10%2F%285sqrt%285%29%29=cos%28theta%29\"\r
\n" ); document.write( "\n" ); document.write( "\"2%2Fsqrt%285%29=cos%28theta%29\"\r
\n" ); document.write( "\n" ); document.write( "\"theta=cos%5E-1%282%2Fsqrt%285%29%29\"\r
\n" ); document.write( "\n" ); document.write( "\"theta=0.463647609\"-> radians\r
\n" ); document.write( "\n" ); document.write( "\"theta=26.57\"°\r
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