## Trigonometry 7th Edition

$x=\frac{\pi}{4}$ or $\frac{5\pi}{4}$, $y=\frac{\pi}{2}$
From the equation, we have $\cos x=\sin x$ and $\sin y=1$. $\cos x=\sin x$ implies $\tan x=1$. $\tan x=1$ when $x=\frac{\pi}{4}$ or $\frac{5\pi}{4}$. $\sin y=1=\sin \frac{\pi}{2}$. That is, $y=\frac{\pi}{2}$.