If $\cot^{-1} x = \frac{3\pi}{4}$, what is $x$?

Explanation

1. 01

   $x = \cot \frac{3\pi}{4}$, and $\frac{3\pi}{4}$ is in $(0, \pi)$.

2. 02

   $\cot \frac{3\pi}{4} = -1$.