Evaluate: `intx^2e^(-x)dx`

Explanation

Integrating by parts,


`u=x^{2}, v=e^x`
`
u=2 x, int v d x=e^{x} `

Rightarrow `x^{2} e^{x}-int 2 x e^{x} d x`


Again integrating by parts, we get


...