document.write( "Question 921229: Find the exact value of the trigonometric expression given that
\n" ); document.write( "sin u =5/13
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\n" ); document.write( "cos v = −3/5
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\n" ); document.write( " (Both u and v are in Quadrant II.)
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Algebra.Com's Answer #558900 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
let A = u and B = v\r
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\n" ); document.write( "\n" ); document.write( "you have:\r
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\n" ); document.write( "\n" ); document.write( "sine of A = 5/13
\n" ); document.write( "cosine of B = -3/5\r
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\n" ); document.write( "\n" ); document.write( "both angles are in the second quadrant.\r
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\n" ); document.write( "\n" ); document.write( "use the pythagorean formula to solve for the missing leg of each triangle.\r
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\n" ); document.write( "\n" ); document.write( "you will get:\r
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\n" ); document.write( "\n" ); document.write( "side opposite A = 5
\n" ); document.write( "side adjacent A = -12
\n" ); document.write( "hypotenuse A = 13\r
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\n" ); document.write( "\n" ); document.write( "side opposite B = 4
\n" ); document.write( "side adjacent B = -3
\n" ); document.write( "hypotenuse B = 5\r
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\n" ); document.write( "\n" ); document.write( "the side adjacent is negative in both triangles because they are both in the second quadrant where the value of x is negative while the value of y is positive.\r
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\n" ); document.write( "\n" ); document.write( "now that you know the sides, you can solve for tangent of A and tangent of B.\r
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\n" ); document.write( "\n" ); document.write( "tangent of A will be equal to 5 / -12 which is equal to -5/12.\r
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\n" ); document.write( "\n" ); document.write( "tangent of B will be equal to 4 / -3 which is equal to -4/3.\r
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\n" ); document.write( "\n" ); document.write( "tangent of A+B is equal to (tangent of A plus tangent of B) divided by (1 - tangent of A * tangent of B).\r
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\n" ); document.write( "\n" ); document.write( "plug values in for the words and you get:\r
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\n" ); document.write( "\n" ); document.write( "tangent of A plus B = ((-5/12) - (4/3)) divided by (1 - (-5/12 * -4/3)\r
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\n" ); document.write( "\n" ); document.write( "do the arithmetic and this turns out to be:\r
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\n" ); document.write( "\n" ); document.write( "tangent of A plus B = -1.75 / .4444444 which is equal to -3.9375.\r
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\n" ); document.write( "\n" ); document.write( "that's your solution.\r
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\n" ); document.write( "\n" ); document.write( "you can translate this back to u and v by letting u = A and v = B and you get:\r
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\n" ); document.write( "\n" ); document.write( "tan(u+v) = -3.9375.\r
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