# How do you find the exact value of cot^-1(-sqrt3/2)?

May 9, 2018

$\arctan \left(- \frac{2}{\sqrt{3}}\right)$ is about as good as answer as any.

#### Explanation:

That one doesn't have the nice answer you might think it would.

A cotangent of $- \frac{\sqrt{3}}{2}$ refers to a right triangle with sides $\sqrt{3}$ and $2$ so hypotenuse $\sqrt{7} .$

$\setminus \frac{\sqrt{3}}{2}$ is a common sine or cosine, but it's not a common cotangent. There's no nice form for this angle.

$\arctan \left(- \frac{2}{\sqrt{3}}\right)$ is about as good as answer as any.