- #1

noahsdev

- 29

- 0

## Homework Statement

Convert -2+2√3

**i**to polar coordinates.

## Homework Equations

r = √x

^{2}+y

^{2}

θ = tan

^{-1}(y/x)

## The Attempt at a Solution

I am confused because θ = tan

^{-1}(2√3/2) = tan

^{-1}(√3) = -π/3 and r = 4, so that would make the polar form 4cis(-π/3), but the calculator gives: 4cis(2π/3).

I think the calculator is right because when I convert my answer (4cis(-π/3)) back to cartesian it gives -2-2√3

**i**, whereas the other (4cis(2π/3))gives the right answer, -2+2√3

**i**.

Can someone explain what I'm doing wrong?

Thanks. :)