4 sin x = 4 cos 2x
- Thread starter Shoezor
- Start date
Unknown008
Junior Member
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- Sep 6, 2011
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Start by breaking the cos(2x) into single angles using one of:
\(\displaystyle \cos(2A) = \cos^2(A) - \sin^2(A) = 2\cos^2(A) - 1 = 1 - 2\sin^2(A)\)
\(\displaystyle \cos(2A) = \cos^2(A) - \sin^2(A) = 2\cos^2(A) - 1 = 1 - 2\sin^2(A)\)
