document.write( "Question 282120: show that cos(3x)/cos(x)=cos^2(x)-3sin^2(x) \n" ); document.write( "
Algebra.Com's Answer #204865 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "\"Cos%283x%29%2FCos%28x%29\"   =    \"Cos%5E2x-3Sin%5E2x\"\r\n" );
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document.write( "\"Cos%282x%2Bx%29%2FCos%28x%29\"\r\n" );
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document.write( "\"++%28Cos%282x%29Cos%28x%29%29%2FCos%28x%29-+%28Sin%282x%29Sin%28x%29%29%2FCos%28x%29+\"\r\n" );
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document.write( "\"++Cos%282x%29-+%28Sin%282x%29Sin%28x%29%29%2FCos%28x%29+\"\r\n" );
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document.write( "\"++Cos%282x%29-+%282Sin%28x%29Cos%28x%29Sin%28x%29%29%2FCos%28x%29+\"\r\n" );
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document.write( "\"++Cos%282x%29-+%282Sin%28x%29cross%28Cos%28x%29%29Sin%28x%29%29%2Fcross%28Cos%28x%29%29+\"\r\n" );
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document.write( "\"++Cos%282x%29-+2Sin%28x%29Sin%28x%29+\"\r\n" );
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document.write( "\"++Cos%282x%29-+2Sin%5E2x+\"\r\n" );
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document.write( "\"++Cos%5E2x-Sin%5E2x-2Sin%5E2x+\"\r\n" );
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document.write( "\"++Cos%5E2x-3Sin%5E2x+\"\r\n" );
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document.write( "Edwin
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