Question

Integrate

(x^2).(e^-x)

with respect to x.

Answer 1

have you tried by parts?

Answer 2

\[u=x^2,dv=e^{-x}\]

Answer 3

I tried that and I got to

-x^2.e^-x+∫e^-x 2xdx

I don't know what to do with that 2xdx when integrating.

Answer 4

repeat the process
that happens a lot in integration by parts

Answer 5

\[u=2x\\dv=e^{-x}\]

Answer 6

indeed, integration by parts applied 2 times :)

Answer 7

Oh right! I got the answer to be

-e^-x . (x^2+2x+2)

thanks for the help guys

Answer 8

:)