Math trig help?

Question

I am trying to do this problem, but I think I keep doing something wrong.
Solve for x, 0< x < 360

2 sin^2x - cos 2x = 0

I tried replacing cos 2x with 1- 2sin^2x, and I keep getting -1 = 0. Is the answer no values?

Answer 1

cos 2x = 1 - 2 sin^2x. Substituting, you get

2sin^2x - (1 - 2sin^2x) = 0

2sin^2x - 1 + 2sin^x = 0

4sin^2x - 1 = 0

sin^2x = 1/4

sinx = +/- (1/2)

x = 30, 150, 210, or 330 degrees

Answer 2

I dont think that cos 2x = 1-2sinx^2 just check trig ID's

Answer 3

change the sin*2 to a simple function using identity. i think like cos2x over something