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Indefinite integral

  • Thread starter menco
  • Start date
  • #1
43
0

Homework Statement


(e^-x)/(1+e^-x)dx


Homework Equations


Integral of e^x function


The Attempt at a Solution


I am completely lost with the problem, the fact that it is e^-x and not e^x has me stupped as well as the division.
 

Answers and Replies

  • #2
354
0
Try [itex]u[/itex]-substitution.
 
  • #3
43
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so if I let u=1+e^-x?
 
  • #4
2,967
5
yes?
 
  • #5
354
0
so if I let u=1+e^-x?
Well, does it work?
 
  • #6
43
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I still cant figure it out so I gave up and will try again later
 
  • #7
354
0
I still cant figure it out so I gave up and will try again later
When you do get back to it, answer this: What is [itex]du[/itex] when [itex]u=1+e^{-x}[/itex]?
 
  • #8
43
0
Will du = -e^-x dx
 

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