SOLUTION: Given that sin^2 beta = sin alpha cos alpha, show that cos 2 Beta = 2 cos^2[π/4 + alpha]
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Question 1118725: Given that sin^2 beta = sin alpha cos alpha, show that cos 2 Beta = 2 cos^2[π/4 + alpha]
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!
\ =\ \cos^2\beta\ -\ \sin^2\beta)
==================
\ =\ \cos\(\frac{\pi}{4}\)\cos\alpha\ -\ \sin\(\frac{\pi}{4}\)\sin\alpha)
)
So
\ =\ 2\(\frac{1}{2}\)\(\cos^2\alpha\ -\ 2\sin\alpha\cos\alpha\ +\ \sin^2\alpha\))
John
My calculator said it, I believe it, that settles it
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