I posted this problem in a different form a year ago! I have encountered it again and would value any suggestions on what approach i should take or what i should read into

This is a part of my equation. i need to evaluate this

where N and S are constants

my problem is that while i can use numerical integration, if the value of N is very large, then i cannot evaluate the exponent (computers can not have integers greater than 1x10^301)

so i want to take the log of that function. That would be trivial without the integral, but i am not sure how to do it with the integral.

How do i take logs? Thanks for ANY help

Chogo