Recent content by moumouer

Thank you very much!

But it still doesn't solve the integral. it became: Integral 2u^2*e^(-u2)sqrt(2a)du

Hi Dick, I read through the article on wiki, and I'm wondering how the parameter a in my problem affect the integral. I cannot ignore a here since the reason I'm calculating E(x) is becoz I'm trying to find the Method of Moment estimator of a. Thank you!

thank you so much!

The question says Let X1...Xn be a random sample from a Rayleigh distribution with pdf f(x) = (x/a)*e-x2/(2a), for x>0. That's it! And I'm suppose to find E(x).

Hi Mark44, I think your method works perfectly w/ my 2nd question. I worked it out already. But I still don't know how to solve the 1st question.

Oh wait a minute, after doing the parts, since V = - (e-x2/(2a)), now applying the fomula, uv - integral v du, how do I solve Integral - (e-x2/(2a)) dx ?

OHHHH! Thank you sooo much! I'v been thinking my head off by trying to do substitution! And I have one more question, I'm required to calculate E(x2) too, so now instead of (X^2)/a for the first part, it becomes (x^3)/a, and the 2nd part remains the same. How do I approach this one? Thank you...

I'm having big trouble when trying to figure this integral out. Please help! Integral (from 0 to infinity): ((x^2)/a)*e^[(-x^2)/2a] dx a is a constantThanks in advance!