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1. The problem statement, all variables and given/known data

I was given an equation with complex numbers, and told to convert to polar coordinates. I was able to find r relatively easily, but finding the angle is giving me trouble- I am having difficulties in breaking the equation down into imaginary and real parts.

The equation:

[tex]\frac{-6}{9+4i}[/tex]

2. Relevant equations

See part 1.

3. The attempt at a solution

I found r by doing the following:

[tex]\frac{|-6|}{|9+4i|}[/tex]

[tex]\frac{6}{\sqrt{81+16}}[/tex]

[tex]r=\frac{6}{\sqrt{97}}[/tex]

Now finding theta is where I get into trouble. I can't seem to understand what to do. I tried just doing it as if all of the fraction was imaginary, which would give me -pi/2 (am I right in thinking this?), but that doesn't work.

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# Homework Help: Complex Numbers

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