D[ 1- ((1- a x)(1- x))^p, {x, 2}]/D[1- ((1-a x)(1- x))^p, {x, 1}]

Uh oh! Wolfram|Alpha doesn't run without JavaScript.

Please enable JavaScript. If you don't know how, you can find instructionshere.Once you've done that, refresh this page to start using Wolfram|Alpha.