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bigdummy3000
May25-09, 04:08 PM
1. The problem statement, all variables and given/known data



integral of 2/((e^(-x))+1)

2. Relevant equations

how do you do this?



3. The attempt at a solution

no freaking clue! this is the BS i came up with

2(x-ln(e^-x + 1) + C)

Dunkle
May25-09, 04:14 PM
You can rewrite the integrand and then use a simple substitution. Hint: multiply the numerator and denominator by e^x and then simplify.

bigdummy3000
May25-09, 05:31 PM
You can rewrite the integrand and then use a simple substitution. Hint: multiply the numerator and denominator by e^x and then simplify.

so then...i want to find the integral of e^x/(e^x + 1)...and i think i want to use substitution? u = e^x + 1. but then i do something wrong somewhere...i'm getting retarded answers...

Cyosis
May25-09, 05:48 PM
If u=e^x+1 then du=?