Find magnitude and angle for v=(sqrt3 , -1) with theta between 0 and 2pi

Question

I came up with a ||v|| of 2 and theta = -1/sqrt3, can someone verify for me? Thanks!

Answer 1

|v| is correct but

Sin^-1(-1/√3) = -35.264 but between 0 and 2Π = 324.74º