How to solve this kind integral?

[dgnephew]

I have looked this kind of integral:

[MATH]\int_0^{\infty}[/MATH]x^3/2e^-axdx, where a is a constant

No success. I appreciate if anyone could help.
Thanks all!

 

[pka]

I have looked this kind of integral: [MATH]\int_0^{\infty}[/MATH]x^3/2e^-axdx, where a is a constant

Lets play the back-of-the-book game: we lookup the answer here.
Seeing the answer should give you a start.

 

[dgnephew]

Thanks, pka.
However, I would like to see the mathmatical procedure.

 

[pka]

Thanks, pka.
However, I would like to see the mathmatical procedure.

That is the game: you see the correct answer and then from there you work out how that answer is gotten.

 

[Steven G]

I agree with pka.

But since you do not want to play that game can you show us what you tried.

We can give you hints using the techniques you tried.

 

[dgnephew]

Ah! OK! Now I understood that "game" you mean.