SOLUTION: Hi, given cos(A+B)= cos A cos B - sin A sin B, Find cos(2x)

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Question 902245: Hi,
given cos(A+B)= cos A cos B - sin A sin B, Find cos(2x)
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
cos(2x) = cos(x + x)= cos^2x - sin^2x = cos^2 - (1-cos^2x) = 2cos^2 - 1