It's the integration of
[x^(3/2)][e^(-x)] from 0 to infinity
I tried to do integration by parts, but that didn't work out.
I know what the answer is but I don't know how to get there.
Any help would be great
Thanks
well if you are willing to use the gamma function, evaluate it at z=5/2
Gamma function - Wikipedia, the free encyclopedia
[quote=Chloe18;379312]
You want to evaluate this:
$\displaystyle
\int_0^\infty x^{\frac{3}{2}}e^{-x}dx
$
And the gamma function is this
$\displaystyle \Gamma (z)=\int_0^\infty t^{z-1}e^{-t}dt$
So $\displaystyle z-1=\frac{3}{2}$
Now I am not aware of a way to evaluate this for non-integer values, not that I'm an expert with the Gamma function, but it seems to me we're back to using tables and calculators