# Finding integral

• September 6th 2012, 04:23 AM
raed
Finding integral
Dears,

I can not find thid integral, anyone can help me?

RegardsAttachment 24711
• September 6th 2012, 04:40 AM
topsquark
Re: Finding integral
Quote:

Originally Posted by raed
Dears,

I can not find thid integral, anyone can help me?

RegardsAttachment 24711

$\int_a^t \frac{pe^{-s}}{1 - p(s - t)}ds$

Note that t and p are constants in the integral. So....
$\int_a^t \frac{pe^{-s}}{1 - p(s - t)}ds = p\int_a^t \frac{e^{-s}}{(1 + pt) - (ps )}ds$

To make this a bit more transparent, let 1 + pt = y, where y is of course a constant.
$\int_a^t \frac{pe^{-s}}{1 - p(s - t)}ds = p\int_a^t \frac{e^{-s}}{y - ps }ds$

What can you do with this?

-Dan