Question

How do you find the polar coordinates of `(-4,0)` ?

Answer 1

The rectangular coordinates `(x,y)=(-4,0)` is equivalent to the polar coordinates `(r,theta)=(4,pi)`

Let us look at some details.

Since `r` is the distance of `(-4,0)` from the origin,

`r=sqrt{(-4)^2+0^2}=4`

Since the segment from the origin to `(-4,0)` makes `180^circ=pi` rad with the positive x-axis,

`theta=pi`