Math Help - binomial coefficient

(1+x)^-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.

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 we define For example

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