document.write( "Question 445214: If cos θ = 3/5 and θ terminates in the first quadrant, find the exact value of sin 2θ. \n" ); document.write( "

Algebra.Com's Answer #306745 by swincher4391(1107) $\"\"$ $\"About$

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We know by our double angle formulas that $\"sin%282theta%29+=+2sin%28theta%29cos%28theta%29\"$
\n" ); document.write( "We are given that $\"cos%28theta%29+=+3%2F5\"$ So construct a triangle with adjacent side 3 and hypotenuse 5. Then following the Pythagorean Theorem, the opposite side of $\"theta\"$ is 4.
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\n" ); document.write( "Thus, $\"sin%28theta%29+=+4%2F5\"$
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\n" ); document.write( "So, $\"sin%282theta%29+=+2%2A%284%2F5%29%2A%283%2F5%29+=+highlight%2824%2F25%29\"$ \n" ); document.write( "

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