pka said:\(\displaystyle e^x = \sum\limits_{k = 0}^\infty {\frac{{x^k }}{{k!}}} \quad \Rightarrow \quad e^{ - t^3 } = \sum\limits_{k = 0}^\infty {\frac{{\left( { - t^3 } \right)^k }}{{k!}}} = \sum\limits_{k = 0}^\infty {\frac{{\left( { - 1} \right)^k t^{3k} }}{{k!}}}\)
grib90 said:Thanks for the reply. Since it's an integral wouldn't you have to integrate it? But how do you deal with factorials when integrating?