# How do you find the endpoint of the radius of the unit circle that corresponds 9π/2 radians?

Oct 31, 2015

First, convert $\frac{9 \pi}{2}$ to less than $2 \pi$

#### Explanation:

$\frac{9 \pi}{2} - \frac{8 \pi}{2} = \frac{\pi}{2}$

So, $\frac{9 \pi}{2}$ is coterminal to $\frac{\pi}{2}$

Now, $\frac{\pi}{2}$ is also ${90}^{o}$ making the endpoint (0,1)

Hope that helped