SOLUTION: Given sin(x)= 2/3 What is the value cos(2x)

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Question 353088: Given sin(x)= 2/3 What is the value cos(2x)
Answer by CharlesG2(834) About Me  (Show Source):
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Given sin(x)= 2/3 What is the value cos(2x)

double-angle cosine formula --> cos(2x) = 1 - 2sin^2(x)

sin(x) = 2/3
sin^2(x) = 4/9
cos(2x) = 1 - 2sin^2(x) = 1 - 2(4/9) = 1 - 8/9 = 1/9