Need some help with exp()

Hey,

Could anyone please explain how to use the <cmath> function exp()? I could really use the help.

Thanks,
Tarls.

exp is used whenever you have to calculate something like : e^x
its different from pow().

syntax=

float res;
res=exp(5); //e^5

Is 'e' always the same? I'm trying to do:

amount = principle * e^(rate * time)

where rate is an annual interest rate, time is in years, and e is 2.71823.

Thanks for the help,
Tarls.

e is a constant, just like pi.