1. Not finding help here? Sign up for a free 30min 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!

Integration questions for my astoronomy class

  1. Apr 2, 2007 #1
    Hi, I have to do alot of integration questions for my astoronomy class but I'm not really sure how to! for example how do u integrate from a number lets say a = 0, to a = 1/(1+z).... and dt = \frac{da}{H_0 \left(\frac{\Omega_{m,0}}{a} + a^2 \Omega_{\Lambda,0}\right)^{\frac{1}{2}}}

    I've done a different kind of simple integration but i have no idea how this works,. thanks!
  2. jcsd
  3. Apr 3, 2007 #2


    User Avatar
    Gold Member

    [tex]dt = \frac{da}{H_0 \left(\frac{\Omega_{m,0}}{a} + a^2 \Omega_{\Lambda,0}\right)^{\frac{1}{2}}} [/tex]

    Is this what you mean ?
  4. Apr 3, 2007 #3


    User Avatar

    To integrate [tex]\frac{du}{(a^2 + b^2 u^2)^{-\frac{1}{2}}}[/tex]
    make the variable change
    [tex]\frac{bu}{a} = tan v[/tex]
    and remember that
    [tex]1 + tan^2 v = sec^2 v[/tex]
  5. Apr 3, 2007 #4
    yest mentz its that one
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?