document.write( "Question 232805: Please help prove identity:
\n" ); document.write( " $\"2sin%282x%29cos%282x%29=4cos%28x%29%28sin%28x%29-2%28sin%28x%29%29%5E3%29\"$
\n" ); document.write( "thank you \n" ); document.write( "

Algebra.Com's Answer #171966 by eggsarecool(46) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"2sin%282x%29cos%282x%29=4cos%28x%29%28sin%28x%29-2%28sin%28x%29%29%5E3%29\"$
\n" ); document.write( "Two formulas you need are $\"sin%282x%29=sin%28x%29cos%28x%29\"$ and the other is $\"cos%282x%29=1-2%28sin%28x%29%29%5E2%29\"$
\n" ); document.write( "Using these we can rewrite the left side to become.
\n" ); document.write( " $\"2%2A2sin%28x%29cos%28x%29%281-2%28sin%28x%29%29%5E2%29\"$ $\"2%2A2=4\"$
\n" ); document.write( " $\"4sin%28x%29cos%28x%29%281-2%28sin%28x%29%29%5E2%29\"$ Now we distribute the $\"sin%28x%29\"$ that is on the outside.
\n" ); document.write( " $\"4cos%28x%29%28sin%28x%29-2%28sin%28x%29%29%5E3%29\"$ this proves your identity.
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