## Trigonometry (11th Edition) Clone

$135^o$
RECALL: $y=\cot^{-1}{x}\longrightarrow \cot{y}=x$, and $0 \lt y\lt 180^o$ Thus, $\theta=\cot^{-1}{(-1)}\longrightarrow \cot{\theta}=-1$ The cotangent function is negative in the second and fourth quadrants. Note that $\cot{135^o} = -1$ Therefore, solving the equation above gives $\theta = 135^o$