# Homework Help: Complex numbers polar form

1. Sep 25, 2012

### Darth Frodo

Not homework as such, just need some clarification.

When finding $\alpha$ do you have to take the signs into account when finding tan$^{-1}$ x/a. Does it matter if a or x are negative?

1: $\theta$ = $\alpha$

2: $\theta$ = $\pi$ - $\alpha$

3: $\theta$ = -$\pi$ - $\alpha$

4: $\theta$ = -$\alpha$

Based on these (if correct) it seems that I should disregard the sign when finding $\alpha$.

Is this correct?

2. Sep 26, 2012

### Saitama

No, signs aren't taken into account while finding $\alpha$.