Question

using the unit circle determine the sine cosine and the tangent functions of the angle -pi/6

Answer 1

This angle is in the 4th segment so only the cosine is positive 

cos pi/6 = sqrt3/2  os cos -pi/6 = sqrt3/2 also

sin -pi/6 = -0.5

tan -pi/6 =  -1 / sqrt3  = - sqrt3/3