# Math Help - binomial coefficient

1. ## binomial coefficient

&#40;1&#43;x&#41;&#94;-0.5 - Wolfram|Alpha

I don't understand the coefficient of the general term given when mod. x <1. I have only seen positive integers before.

2. ## Re: binomial coefficient

Originally Posted by Stuck Man
I don't understand the coefficient of the general term given when mod. x <1. I have only seen positive integers before.
If $p\in\mathbb{R},\;n\in \mathbb{N}$ we define $\displaystyle\binom{p}{n}=\dfrac{p(p-1)\ldots (p-n+1)}{n!}.$ For example $\displaystyle\binom{-0.5}{3}=\dfrac{(-0.5)(-0.5-1)(-0.5-2)}{3!}=\ldots$

3. ## Re: binomial coefficient

Thanks. I thought that way of evaluating nCr was simply convenient sometimes.