- #1
sirhc1
- 4
- 0
Homework Statement
[itex]\int_0^∞ x^2exp(-x/2) dx[/itex]
Homework Equations
The Attempt at a Solution
Using u substitution:
u = x/2
du = 1/2 dx
[itex]\int_0^∞ 4u^2exp(-u) du*2[/itex]
= 8 [itex]\Gamma(3)[/itex]
= 8*3!
= 48
But the correct answer is 16 when I plug it in Wolfram's definite integral calculator. I don't see where's my mistake?
Thank you very much!