Решите уравнение: ctg^2*x + 3sinx+1 = (1/sin^2x) +3

Cos^2*x/ sin^2*x +3sinx +1 = 1/ sin^2*x +3
( cos^2*x - 1) /sin^2*x +3sinx - 2 =0
- sin^2*x / sin^2*x +3sinx - 2 =0
- 1 +3sinx -2 = 0
3 sinx = 3
sinx = 1
x = п/2 + 2пn? n принадлежит Z