Solve 4 cos2 x cot2 x for all solutions 0 lessthanorequalto

Solve 4 cos^2 x = cot^2 x for all solutions 0 lessthanorequalto x

4cos^2x = cos^2x

4cos^2x = cos^2x/sin^2x

cos^2x gets cancelled:

4 = 1/sin^2x

4sin^2x -1 =0

sinx = +/- 1/2

sin= 1/2 ----> x= pi/6 , pi-pi/6

x= pi/6 , 5pi/6

sin = -1/2

x= pi +pi/2 , 2pi -pi/6

x= 3pi/2 , 11pi/6

Solution : x= pi/6 , 5pi/6 , 3pi/2 , 11pi/6