Integration by parts is used when integrating the product of functions.
The formula is:
∫udv=uv−∫vdu
Choose:
- u=x
- dv=exdx
Then:
- du=dx
- v=ex
∫xexdx=x⋅ex−∫ex⋅dx
=xex−ex
=ex(x−1)
Applying the limits from 0 to 1:
∫01xexdx=[ex(x−1)]01
At x=1:
e1(1−1)=0
At x=0:
e0(0−1)=−1
∫01xexdx=0−(−1)
=1
Therefore, the answer is 1.