Integrating By Parts: Is 4 Times Best for \int {x^4 e^x dx}?

[danago]

Hi. When evaluating an integral such as:

<br /> \int {x^4 e^x dx} <br />

Is integrating by parts 4 times the best method, or is there a more efficient way?

Thanks in advance,
Dan.

 

[JonF]

I think you are going to have to do parts 4 times.

 

[rock.freak667]

Well if the problem was a definite integral for example say:
\int_{0}^{1} x^4e^x dx

you could easily make a reduction formula for easy calculations. But that is a different question altogether. As previously stated you would have to integrate by parts at 4 times

 

[danago]

Alright, thanks for the replies guys