# Complex numbers polar form

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?

## Answers and Replies

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

I am not sure about the 3 quadrant.