Question

solve for x:

sin(x)=2*cos(2*x)

Answer 1

cos(2x) = cos^2x - sin^2x = 1-2sin^2x
So, you have:
sin(x) = 2(1-2sin^2x).

Treat sin(x) as t. You have
t = 2(1-2t^2). Solve like the quadratic equation. Find values of t. Since t = sin(x), find x.

Answer 2

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