Originally Posted by

**rainer** Hello,

I need to integrate this based on certain information. I've tried integration by parts, looked in tables, etc., and am pretty sure there's just no neat way to do it. But I want to check with the forum before I give up.

$\displaystyle \int \frac{dx}{dt} e^t \: dt$

The information I have:

1) $\displaystyle x=x(t)$

2) $\displaystyle \frac{d\ln{f_x}}{dt}=1$

(where the notation $\displaystyle f_x=\frac{df}{dx}$)

3) $\displaystyle \frac{df}{dx}=e^t$

(3 can be deduced from 2 or vice versa)

Thanks