#### Answer

The equivalent trigonometric form of $-3 - i$ is $\sqrt{10}cis198.435^\circ$ or $\sqrt{10}(cos198.435^\circ + isin198.435^\circ)$.

#### Work Step by Step

$-3 - i$ is at $arctan(\frac{-1}{-3})+180^\circ = 198.435^\circ$ with absolute value $\sqrt{(-3)^2 + (-1)^2} = \sqrt{10}$. The equivalent trigonometric form of $-3 - i$ is $\sqrt{10}cis198.435^\circ$ or $\sqrt{10}(cos198.435^\circ + isin198.435^\circ)$.