Question 155191
(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.