Answer
$\frac{\pi}{4},\frac{3\pi}{4},\frac{5\pi}{4},\frac{7\pi}{4}$
Work Step by Step
1. $tan\theta=cot\theta \Longrightarrow tan^2\theta=1 \Longrightarrow tan\theta=\pm1$,
2. $tan\theta=1 \Longrightarrow \theta=\frac{\pi}{4},\frac{5\pi}{4}$ in $[0,2\pi)$,
2. $tan\theta=-1 \Longrightarrow \theta=\frac{3\pi}{4},\frac{7\pi}{4}$ in $[0,2\pi)$.
