Question

How do you find the polar coordinates of the point `(-2,0)` ?

Answer 1

The polar coordinates of `(x,y)=(-2,0)` is `(r,theta)=(2,pi)`.

Since the distance of the point from the origin is `sqrt{(-2)^2+(0)^2}=2`,
so `r=2`.

Since the line segment (vector) from the origin to (-2,0) and
the positive x-axis makes `180^circ`, whcih is `pi` radians; therefore, `theta=pi`.