document.write( "Question 265625: cos2x=(cos^2)x-(sin^2)x \n" ); document.write( "
Algebra.Com's Answer #195283 by roseo(33)\"\" \"About 
You can put this solution on YOUR website!
This is a trig identity (double angle formula) therefore all values of x will work in this equation. \n" ); document.write( "
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