1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The Marginal pdf of a Function

  1. Mar 17, 2010 #1
    1. The problem statement, all variables and given/known data The integral from 0 to infinity of xe^[-x(1+y)]dy



    2. Relevant equations



    3. The attempt at a solution
    3105697.jpg

    I can't figure out why the answer would be zero to a pdf. Also, for the indefinite integral the calculator produces the answer xy*e^(-x-xy). I cant' figure out how to get that answer, nor can I figure out if it would even matter if I was able to.

    I guess I'm just asking for another set of eyes to look over my work and see if there is something that I am missing.
     
  2. jcsd
  3. Mar 17, 2010 #2
    aren't you supposed to get -e^(-x)
    ?

    when you plug 'b' into y, the term becomes zero.
    but when you plug zero, it becomes -e^(-x)*1
     
  4. Mar 17, 2010 #3
    Yes! You're right! Something was bugging me about that big fat zero. I knew I needed another set of eyes. Thanks a lot!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: The Marginal pdf of a Function
  1. Marginal PDF Problem (Replies: 4)

Loading...