document.write( "Question 981589: For all real numbers x, Nb \n" ); document.write( "
Algebra.Com's Answer #602587 by Fombitz(32388)\"\" \"About 
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By identity,
\n" ); document.write( "\"cos%282x%29=cos%5E2%28x%29-sin%5E2%28x%29\"
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