If f(sin x) = cos 2x, find f(cos x).

Expert Answers

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It is given that f(sin x) = cos 2x. We have to determine f(cos x)

cos x = sin (90 - x)

f(sin (90 - x)) = cos (2*(90 - x))

=> cos (180 - 2x)

=> -cos 2x

For the given function, f(cos x) = -cos 2x

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