- #1

cepheid

Staff Emeritus

Science Advisor

Gold Member

- 5,196

- 38

[tex] \sum_{n = -\infty}^{-1} \left(\frac{1}{2}e^{-j \omega} \right)^n [/tex]

I tried rewriting it like this:

[tex] \sum_{m = 1}^{\infty} (2e^{j \omega})^m [/tex]

m = -n

but I'm not sure if that helps.