The rectangular coordinates of a point are given. Find polar coordinates of the point.

Question

The rectangular coordinates of a point are given. Find polar coordinates of the point.

(3,-3)

Answer 1

(3, -3) = (3sqr2, 7pi/4) = (r, theta)

x = rcostheta, r=x/costheta

y =rsintheta r=y/sintheta

r^2 = x^2 +y^2= 18

r = sqr18 = 3sqr2