Write the expression and evaluate. There should only be one answer which should match the range of the inverse trig function.

Sec^-1(-2)
sec^-1(-sqrt2)
Cos^-1((-sqrt3)/2)
Tan^-1(-sqrt3)
Could someone explain how to get the answer as well please.

To limit the results to only one answer, the range must be limited to a

value between 0 and 180 degrees:
0 < A < 180.

secA = 1/cosA = -2,
cosA = -1/2,
A = 120 deg.

secA = 1/cosA = -sqrt2,
cosA = -1/sqrt2,
A = 135 deg.

cosA = -(sqrt3)/2,
A = 150 deg.

tanA = -sqrt3,
A = -60 deg.,CW = -60 + 180 = 120 deg.