Question:
Evaluate the following integrals:
$\int \frac{e^{2 x}}{e^{2 x}-2} d x$
Solution:
Assume $e^{2 x}-2=t$
$d\left(e^{2 x}-2\right)=d t$
$\Rightarrow 2 e^{2 x} d x=d t$
$\Rightarrow e^{2 x} d x=\frac{d t}{2}$
Put $\mathrm{t}$ and $\mathrm{dt}$ in the given equation we get
$\Rightarrow \frac{1}{2} \int \frac{\mathrm{dt}}{\mathrm{t}}$
$=\frac{1}{2} \ln |\mathrm{t}|+\mathrm{c}$
But $t=e^{2 x}-2$
$=\frac{1}{2} \ln \left|e^{2 x}-2\right|+c$