Now you try

For each of the following, find $u$ and $v^{\prime }$ to simplify these integrals using integration by parts:

1. 3)

   $$\int x{e}^{-x}𝑑x$$

2. 4)

   $$\int x{e}^{-x^2}𝑑x$$

   (As discussed in class, this is a bit of a trick question.)

3. 5)

   $$\int x^2{e}^{-x}𝑑x$$