# How do you find the terminal point p(x,y) on the unit circle determined by the giving value of t= (-3pi)/4?

Aug 30, 2015

$\left(- \frac{\sqrt{2}}{2} , - \frac{\sqrt{2}}{2}\right)$
The coordinates of the terminal point would be$x = \cos \left(\frac{- 3 \pi}{4}\right) , y = \sin \left(\frac{- 3 \pi}{4}\right)$
$x = \cos \left(\frac{3 \pi}{4}\right) = \cos \left(\pi - \frac{\pi}{4}\right) = - \cos \frac{\pi}{4} = - \frac{\sqrt{2}}{2}$
$y = \sin \left(\frac{- 3 \pi}{4}\right) = - \sin \left(\frac{3 \pi}{4}\right) = - \sin \left(\pi - \frac{\pi}{4}\right) = - \sin \frac{\pi}{4} = - \frac{\sqrt{2}}{2}$