Mathematics

Problem

Let

f(x) = e^{\cos^{-1} \sin(x + \pi/3)}

then a.

f\left(\frac{8\pi}{9}\right) = e^{5\pi/18}

f\left(\frac{8\pi}{9}\right) = e^{13\pi/18}

f\left(-\frac{7\pi}{4}\right) = e^{\pi/12}

f\left(-\frac{7\pi}{4}\right) = e^{11\pi/12}