Question

Find the exact value of the composition. arccos (cos pi/2)

Answer 1

arccos (cos pi/2)=?
cos pi/2=0, arccos (0)=?, we know that cos pi/2=0, so cos^-1 (o)= Pi/2, but cos^-1 (o)=arccos (0), so arccos (cos pi/2)=Pi/2