You are Here: Home >< Maths

# Partial fraction/binomial expansion question

Announcements Posted on
Four hours left to win £100 of Amazon vouchers!! Don't miss out! Take our short survey to enter 24-10-2016

1. I have a problem with understanding the point of the second part of the question. How to get an expansion of f(x) when it can go on forever? If I get an expression taking just till the coefficient of x^3 then it's a meaningless expression, and is incomplete?
2. you will get two separate expansions, one for each of the underneath brackets... select the terms in each up to x3 and combine them together.
as you say the whole expansion will be infinite but just keeping the low powers is very useful.
3. If you are pedantic, put "..." after the expansions to indicate they continue

For example

4. (Original post by bmqib)

I have a problem with understanding the point of the second part of the question. How to get an expansion of f(x) when it can go on forever? If I get an expression taking just till the coefficient of x^3 then it's a meaningless expression, and is incomplete?
It is not meaningless

Since |x|<1 the higher powers of x are very small values

Therefore a small number of terms will give a good approximation

## Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: April 10, 2012
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Today on TSR

### Who is getting a uni offer this half term?

Find out which unis are hot off the mark here

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read here first

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams