Question 190899
Just in case you don't remember:
Given the polar coordinates of a point (r, theta) then it rectangular coordinates is (r cos theta, r sin theta).
---
Here:
r=5
theta=2pi/3=120 degrees
---
{{{x=r cos theta = 5 cos 120=5(-1/2)=-5/2}}}
{{{x sin theta = 5 sin 120=5sqrt(3)/2}}}
So, the rectangular coordinates of the given point is:
({{{-5/2}}}, {{{5sqrt(3)/2}}})