document.write( "Question 889588: Prove the identity:\r
\n" ); document.write( "\n" ); document.write( "[cos^4(x)-sin^4(x)]/[cos(x)+sin(x)] = cos(x)-sin(x) \n" ); document.write( "
Algebra.Com's Answer #538257 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "\"%28cos%5E4%28x%29-sin%5E4%28x%29%29%2F%28cos%28x%29%2Bsin%28x%29%29\"\"%22%22=%22%22\"\"cos%28x%29-sin%28x%29\"\r\n" );
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document.write( "\"%28%28cos%5E2%28x%29-sin%5E2%28x%29%29%281%29%29%2F%28cos%28x%29%2Bsin%28x%29%29\"\r\n" );
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document.write( "\"%28cos%5E2%28x%29-sin%5E2%28x%29%29%2F%28cos%28x%29%2Bsin%28x%29%29\"\r\n" );
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document.write( "\"cos%28x%29-sin%28x%29\"\r\n" );
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document.write( "Edwin
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