document.write( "Question 1009527: For all real numbers x, cos2(x)-sin2(x)= \n" ); document.write( "
Algebra.Com's Answer #625013 by fractalier(6550)\"\" \"About 
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cos^2(x) - sin^2(x) = cos(2x)
\n" ); document.write( "Basic double-angle identity.
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