Question

integrate e^x / 1+e^x

Answer 1

use u-substitution

u=(1+e^x)

Answer 2

are you familiar with u-substitution?

Answer 3

\(u=1+e^x\), \(du=e^xdx\)

Answer 4

oh! thank you!

Answer 5

no problem :)

Answer 6

I got ln 1+e^x+c is this correct?

Answer 7

nope :/

Answer 8

Wolfram|Alpha is a great website for checking answer :)

Answer 9

\[\hspace{11pt}\int\frac{e^x}{1+e^x}dx\]\[=\int\frac1udu\]\[=\ln u+c\]\[=\frac1{1+e^x}+c\]