Only using the Comparison test, I am trying to see if the following integral converges: $$\int_0^{\infty} \frac{\arctan x} {2+e^{x}} \ dx$$
I first noted that $\arctan x \lt (2+e^{x}) \ \forall x \in \mathbb{R}$ which allows me to say that
$$\int_0^{\infty} \frac{\arctan x} {2+e^{x}} \ dx \lt \infty$$
I'm not sure where to progress from here though.
Mathematica reports the integral converging to $\approx .408108504052.$
Best Answer
HINT
$\vert\arctan(x)\vert \in \left[ 0, \pi/2\right]$ and $2+e^x > e^x$. Can you now finish it off?