Polar coordinates
[tex](r, \theta) = (-7, \dfrac{5 \pi}{3})[/tex]
We convert to rectangular coordinates using
[tex](x,y)=(-7 \cos \dfrac{5 \pi}{3} , -7 \sin \dfrac{5 \pi}{3})[/tex]
We'll negate the angle (and add two pi) which negates the sine but leaves the cosine alone.
[tex](x,y)=(-7 \cos \dfrac{\pi}{3}, 7 \sin \dfrac{\pi}{3})[/tex]
Of course 60 degrees is the biggest cliche in trig.
[tex](x,y) = (-7 (\dfrac 1 2), 7( \dfrac{\sqrt{3}}{2}) ) [/tex]
[tex](x,y) = (-\dfrac{7}{2}, \dfrac{7\sqrt{3}}{2} )[/tex]
