document.write( "Question 1107683: How to prove that $\"sinxcos%5E3x-cosxsin%5E3x=%281%2F4%29%28sin4x%29\"$ ? \n" ); document.write( "

Algebra.Com's Answer #722712 by ikleyn(52848) $\"\"$ $\"About$

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document.write( "   =  = \r\n" );
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document.write( "     Use the basic trigonometric formulas  sin(x)*cos(x) = ,   cos^2(x)-sin^2(x) = cos(2x)  to get\r\n" );
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document.write( "=  =  //use again  sin(2x)*cos(2x) =   to get //   = .\r\n" );
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document.write( "That's all.\r\n" );
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