- #1

jey1234

- 38

- 0

## Homework Statement

I am doing a poof and I need to use the binomial theorem. However is the following a correct way to rewrite it?

[tex](a+b)^n\ =\ {n \choose 0}a^{n} + \sum_{k=1}^{n}{n \choose k}\ a^{n-k}\ b^{k} [/tex]

## Homework Equations

[tex](a+b)^n\ =\ \sum_{k=0}^{n}{n \choose k}\ a^{n-k}\ b^{k} [/tex]

## The Attempt at a Solution

Basically, I want to extract the first term of the binomial expansion out of the summation but I'm not that good with sigma notation. Don't I just have to increase the lower bound by 1 and write the first term outside (as shown above)? Thanks.