Find the general solution : `sin 2x + cos x = 0`

Answer

`x=(2n+1) pi/2` or `x=n pi + (-1)^n (7 pi)/6, n in ZZ`

Explanation

`sin 2x + cos x = 0`

`2 sin x cos x + cos x = 0`

`cosx(2 sinx+1)=0`

`cosx = 0` or `sinx = -1/2`

`x=(2n+1)\ pi/2` or `x=n pi + (-1)^n\ (7 pi)/6, \ n in ZZ`