SOLUTION: Prove the identity. (must work with left side) (1-2sin(x)^2)=(cos(x)^2)

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Question 155191This question is from textbook precalculus
: Prove the identity. (must work with left side)
(1-2sin(x)^2)=(cos(x)^2) This question is from textbook precalculus

Answer by stanbon(29602) About Me  (Show Source):
You can put this solution on YOUR website!
(1-2sin(x)^2)=(cos(x)^2)
sin^2(x) + cos^2(x) - 2sin^2(x) = cos^2(x)
cos^2(x) - sin^2(x) = cos^2(x)
-sin^2(x) = 0
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The original problem is NOT an identity.
It leads to a statement that is true only for certain values of "x".
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Cheers,
Stan H.