2007-10-13 04:59:31 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
If you're looking for an indefinite integral, then there is no closed form expression.
exp(x) / x = 1/x + ∑ x^n / (n+1)!
So integrating we get
ln|x| + ∑ x^(n+1) / [(n+1)*(n+1)!]
2007-10-13 09:59:01 · answer #1 · answered by Dr D 7 · 2⤊ 0⤋
Take 1/x=a
Therefore the question becomes a[e^(-a)] ie.. (exp -a)/a.
Now use integration by parts or apply Bernoulli's formulae which is an extension of integration by parts.
After applying Bernoulli's formulae substitute a=1/x.
You will find Ur answer. I hope my method would have been helpful to you. Rate me best if you me find useful......
2007-10-13 12:12:36 · answer #2 · answered by shivenius 2 · 1⤊ 2⤋
So sorry, but this function has no elementary
antiderivative. Its integral defines a new
function Ei(x), the exponential integral of x.
2007-10-13 12:18:27 · answer #3 · answered by steiner1745 7 · 2⤊ 2⤋