Does $f(x)=\frac1x\int_0^x\frac{1}{\sin t+\sin (\pi t)+2}dt$ have a supremum?
(This question was inspired by What is the mean value of $|\sin x +\sin (\pi x)|$?.)
My thoughts:
$\frac{1}{\sin t+\sin (\pi t)+2}$ can be arbitrarily large, but that doesn't tell me whether its average value from $t=0$ to $t=x$, for all $x\in\mathbb{R}$, has a supremum.
Wolfram does not evaluate $\int \frac{1}{\sin t+\sin (\pi t)+2}dt$.
Here is the graph of $y=\frac1x\int_0^x\frac{1}{\sin t+\sin (\pi t)+2}dt$ from $x=-30$ to $x=30$.