Answer
$\int\frac{e^{x}}{e^{x}+1}dx=ln(e^{x}+1)+constant$
Work Step by Step
Evaluate $\int\frac{e^{x}}{e^{x}+1}dx$
Consider $e^{x}+1=t$
and
$e^{x}dx=dt$
Thus, $\int\frac{e^{x}}{e^{x}+1}dx=\int \frac{dt}{t}$
$=ln|t|+constant$
$=ln(t)+constant$
Hence, $\int\frac{e^{x}}{e^{x}+1}dx=ln(e^{x}+1)+constant$