Question

sinv=1/4 what is cos(2v)?

Answer 1

do you know a way to express sine in terms of cosine?

Answer 2

no haha

Answer 3

not too sure how to go about this?

Answer 4

Use these steps
\[ \cos x = \sqrt{1-\sin^2x} \]
\[ \cos^2 x = 1-\sin^2 x \]
\[ \cos 2x = 1 - 2 \sin^2x \]

Answer 5

cos2x=1-(1/16)

Answer 6

well... cos2x=1-2sin1/16?

Answer 7

\[\cos \left(2 \ \sin ^{-1}\left(\frac{1}{4}\right)\right)=0.875 \]

Answer 8

cos2x=1-(2/16)
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