What is the Cartesian form of (100,7π12)?

${\displaystyle x=r\cos \theta }$ 
${\displaystyle y=r\sin \theta }$ 
Explanation: 
First, note that ${\displaystyle \frac{7\pi }{12}}$ is in Quadrant II which means the x-coordinate will be negative and the y-coordinate positive. 
Using the name given above... 
${\displaystyle x=100\cos \left(\frac{7\pi }{12}\right)\approx -25.88}$ 
${\displaystyle y=100\sin \left(\frac{7\pi }{12}\right)\approx 96.59}$ 
Therefore, Cartesian Form: (-25.88, 96.59)