What is the arctangent of -1/√3 using the unit circle?

What is the value of 0, using unit circle?

 As x coordinate approaches zero and y is any positive real number, then the value (degree) of arctangent approaches:

What is the arctangent of √(1/3) using the unit circle?

Evaluate (-√3) using the unit circle.           

Evaluate (-1) using the unit circle.

If tan (x) =  √(1/3) using unit circle, what is the value of √(1/3) ?

Evaluate √3 using the unit circle. 

If x -coordinate iszero and y is any negative real number, then the value (degree) ofarctangent approaches:

What is the arctangent of 0.5 ?