Solve the given equation in the interval [0,2 $\pi$].
Note: The answer must be written as a multiple of $\pi$. Give exact answers. Do not use decimal numbers. The answer must be an integer or a fraction. Note that $\pi$ is already provided with the answer so you just have to find the appropriate multiple. E.g. if the answer is $\frac{\pi}{2}$ you should enter 1/2. If there is more than one answer write them separated by commas.

$2(\sin x)^2-5 \cos x +1 = 0$

$x$= $\pi$