Examples

The video below works out some integration by parts examples. 




After watching the video, see if you can compute the same examples without looking back at the video:

1)  DO:  Compute $\displaystyle \int x \ln(x)\,dx$, letting $u=\ln(x)$ and $dv=x\,dx$.  Be careful and precise with where you write $u$ and $dv$ as in the video - do it the same way every time to keep from making errors.  (Notice that you cannot let $dv=\ln x$, since you do not (yet) know the antiderivative of $\ln x$.)


2)  DO:  Compute $\int x \sin(x)\,dx$, letting $u=x$ and $dv=\sin(x)\, dx$.

3)  DO:  Set up $\int x \sin(x)\,dx$ (the same integral as above), but this time letting $u=\sin x$ and $dv=x\, dx$.  What do you think about this integral $\displaystyle\int v\,du$?  It is fine to try one way, then decide it might be better another way!

  • 4)  DO:  Compute $\int x^2 e^x\,dx$.  What would you choose for $u$ and $dv$ and why?  Remember, you want your resulting integral $\displaystyle \int v\,du$ to be simple to compute.

  • If you need help on these examples, rewatch the video.