Question

Find the rectangular coordinates of the point with the polar coordinates (-7, 5pi/3)

Answer 1

$\left(7\cdot\cos \dfrac{5\pi}{3},7\cdot\sin\dfrac{5\pi}{3}\right)=\left(7\cdot\dfrac{1}{2},7\cdot\left(-\dfrac{\sqrt3}{2}\right)\right)=\\ \left(\dfrac{7}{2},-\dfrac{7\sqrt3}{2}\right)$