i been trying to solve this but can't seem to get the wrong answer, can anyone help me located where i went wrong?

3cot^2(x)=1 , x is greater than or equal to 0 and less than 2pi

cot(x) = 1/square root 3

x = 60 degree or pi / 3

shouldn't the 4 answers be pi/3, -2pi/3, 4pi/3, and -5pi/3

correct me if im wrong please. thank you!