Question #5fb99

1 Answer
Jul 25, 2017

No solution with elementary functions

Explanation:

Substitute #u=e^(-x)#, #x=-ln(u)#.

#"d"u = -1/e^(-x) "d"x#.

Integral is transformed to

#-int ln(1-u)/u "d"u#.

This is an integral that cannot be solved with the use of elementary functions. It's solution is a function called Spencer's function which you can read about here.