# Math Help - Graphical Interpretation For Division

1. ## Graphical Interpretation For Division

I have looked all through my text book and even bought a pre-calc for dummies but I cannot find the correct way to graph this. I was supposed to create my own equation solve then show a graphical interpretation showing how to divide complex numbers solely using the graph of each complex number.
I did the equation 7 + 4i/2-5i with the end result being -6/29 + 43/29i. I talked to my coach about this and she told me to google the parallelogram theorem but so far I am not finding anything that can help me. Can someone please help break this down for me?

2. ## Re: Graphical Interpretation For Division

Originally Posted by princeslolypop
I have looked all through my text book and even bought a pre-calc for dummies but I cannot find the correct way to graph this. I was supposed to create my own equation solve then show a graphical interpretation showing how to divide complex numbers solely using the graph of each complex number.
I did the equation 7 + 4i/2-5i with the end result being -6/29 + 43/29i. I talked to my coach about this and she told me to google the parallelogram theorem but so far I am not finding anything that can help me. Can someone please help break this down for me?
You should know that if $\displaystyle z_1 = r_1\,\textrm{cis}\,\theta_1$ and $\displaystyle z_2 = r_2\,\textrm{cis}\,\theta_2$, the rule for multiplying complex numbers is

$\displaystyle z_1z_2 = r_1r_2\,\textrm{cis}\left(\theta_1 + \theta_2\right)$

It follows that division of complex numbers is

$\displaystyle \frac{z_1}{z_2} = \frac{r_1}{r_2}\,\textrm{cis}\left(\theta_1 - \theta_2\right)$