How Can I Find the Power Series Representation of the Given Integral Function?

Join the discussion
Registration is free. Start your own thread to ask a follow-up.
1 reply · 2K views
girolamo
Messages
6
Reaction score
0
Hi, I'm trying to find the series representation of [tex]f(x)=\int_{0}^{x} \frac{e^{t}}{1+t}dt[/tex]. I have found it ussing the Maclaurin series, differenciating multiple times and finding a pattern. But I think it must be an eassier way, using the power series of elementary functions. I know that [tex]e^{x}=\sum_{0}^{\infty}\frac{x^{n}}{n!}[/tex] and [tex]\frac{1}{1+x}=\sum_{}^{\infty}(-1)^{n}x^{n}[/tex] but I don't know how to use it here. Thanks

(Don't hesitate to correct my english)
 
Physics news on Phys.org
If ##f(x) = \sum_{n=0}^\infty a_n x^n## then
##\frac{f}{1-x} = \sum_{n=0}^\infty \sum_{j=0}^n a_j x^n##.