Answer
$\dfrac{-\pi}{2} \leq \theta \leq \dfrac{-\pi}{2}$ and $1\leq r\leq 4$
Work Step by Step
It can be seen that the radius goes from $1$ to $4$ and the angle $\theta$ goes from $\dfrac{-\pi}{2}$ to $\dfrac{\pi}{2}$. Therefore, the region described in polar coordinates is:
$\dfrac{-\pi}{2} \leq \theta \leq \dfrac{-\pi}{2}$ and $1\leq r\leq 4$.
