Question 1165239
Values of trig functions
{{{cot(-120) = 1/tan(-120)}}}
{{{cot(-120)=1/tan(-120+360)}}} when you add 360 its ok and will produce same value because it just means one circle, or one revolution
{{{cot(-120)=1/tan(240)}}}
We all know that
tan 240° = tan (180°+60°)
And tan(180)=0 leaving us with tan(60°)
And we all know that the value for tan(60) is = √3
∴tan 240°=√3
{{{cot(-120)=1/tan(240)}}}
cot(-120)=(1/√3) 
cot(-120)=(1/√3)(√3/√3) we multiply  √3/√3 to rationalize

Therefore:
cot(-120)=(√3/3) 

Hope that helps.