Split : into partial fractions and hence expand the expression in power series in x up to to the term in What is the term in ?
The expression in partial fractions is However, I don't know how to expand it in power series.
No I will not. If you are an EE you should know this stuff. I walked you to the answer. If you would do a simple google search you might find this
Geometric series - Wikipedia, the free encyclopedia
with what i said above you can solve the question.
PM if you can justify that things are otherwise.
(Also look at the earlier posts, you have been given everything you need (line 11 after "Formula") to do this problem short of TheEmptySet typing out what is on the link he gave again)