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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


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    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


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    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
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