document.write( "Question 24448: For all real numbers x, cos^2(x) - sin^2 (x)=?\r
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Algebra.Com's Answer #13504 by venugopalramana(3286)\"\" \"About 
You can put this solution on YOUR website!
THIS IS A STANDARD FORMULA AND IS EQUAL TO COS (2X)...THERE IS NOTHING MORE TO IT UNLESS YOU ARE TO PROVE THIS FORMULA.PLEASE GIVE ME YOUR COURSE OF STUDY AND YOUR BACK GROUND KNOWLEDGE SO THAT I CAN GIVE FURTHER ADVICE. \r
\n" ); document.write( "\n" ); document.write( "cos^2(x) - sin^2 (x)=?=COS(2X)\r
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