document.write( "Question 902245: Hi,\r
\n" ); document.write( "\n" ); document.write( " given cos(A+B)= cos A cos B - sin A sin B, Find cos(2x) \n" ); document.write( "

Algebra.Com's Answer #547184 by ewatrrr(24785) $\"\"$ $\"About$

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cos(2x) = cos(x + x)= cos^2x - sin^2x = cos^2 - (1-cos^2x) = 2cos^2 - 1 \n" ); document.write( "

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