How do you integrate int x^2e^(x-1)dx using integration by parts?

1 Answer
Jun 30, 2018

The answer is =e^(x-1)(x^2-2x+2)+C

Explanation:

The integral is

I=intx^2e^(x-1)dx=1/eintx^2e^xdx

Perform an integration by parts

intuv'=uv-intu'v

Here,

u=x^2, =>, u'=2x

v'=e^x, =>, v=e^x

The integral is

I=1/e(x^2e^x-2intxe^xdx)

Apply the integration by parts once more

u=x, =>, u'=1

v'=e^x, =>, v=e^x

Therefore,

intxe^xdx=xe^x-inte^xdx=xe^x-e^x

Finally,

I=1/e(x^2e^x-2(xe^x-e^x))+C

=e^x/e(x^2-2x+2)+C

=e^(x-1)(x^2-2x+2)+C