Integrating exponentials and complex numbers: Why does this equality hold? I'm looking at a physics problem and I'm having trouble to understand why the following equality holds:
$\int{p e^{\frac{i}{h}xp}dp}=\int{\frac{h}{i}\frac{d}{dx}[e^{\frac{i}{h}xp}]dp}$
I would be grateful if someone could clarify the steps in between. Also, note that i stands for the imaginary unit and h is just a constant. Thanks.

In general, for any constant $a$,
$$\frac{d}{dx}e^{ax}=ae^{ax}.$$
Now, in $\frac{d}{dx}e^{\frac ihxp}$, $p$ is merely a constant (since we're differentiating with respect to $x$). Can you proceed from here?
