Answer
($\frac{\sqrt 2}{2}$, $\frac{\sqrt 2}{2}$)
Work Step by Step
If you look at the unit circle, you cannot locate $\frac{-7\pi}{4}$. You have to add 2$\pi$, a full unit circle rotation, to it. You end up with $\frac{\pi}{4}$, an angle that's coterminal to $\frac{-7\pi}{4}$ and is between 0 and 2$\pi$. Look at the unit circle and find its corresponding terminal point.
