Question

tan(sec-1sqrt(2))

Answer 1

sec^-1 sqrt 2, the angle with a secant of sqrt 2, is the angle with cosine of 1/sqrt2, which is 45 degrees. The tangent of that angle is exactly 1.

Another angle with a sec of sqrt2 is 315 degrees. The tangent of that angle is -1. So there are two possible answers.

Answer 2

Thank you so much, drwls. I understand it now!