What does arcsin(cos(2π3)) equal?

2 Answers
Feb 26, 2016

π/6

Explanation:

cos (2π/3 ) = sin ( π/2 + (2π/3))=sin(pi#/6)
arc sin (sin) is unit operator 1.

Feb 26, 2016

(7pi)/6 and (11pi)/6

Explanation:

On the trig unit circle,
cos(2π3)==cos(2π)3=12
sinx=12 --> arc x=π6 and x=5π6.
Answer using positive arcs (co-terminal arcs):
x=7π6 and x=11π6