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Qucik Question

  1. May 14, 2005 #1
    How does pi(y/2pi)^2 = y^2/4pi????

    I am confussed.

  2. jcsd
  3. May 14, 2005 #2
    [tex]\pi \left(\frac {y} {2\pi}\right)^2 = \frac {\pi y^2} {(2\pi)^2} = \frac{\pi y^2} {4\pi^2} = \frac {y^2} {4\pi}[/tex]
    Last edited: May 14, 2005
  4. May 14, 2005 #3


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    In short and abstract form

    [tex] \left(\frac{a}{b}\right)^{2}=\frac{a^{2}}{b^{2}} [/tex]


    [tex] \left(ab\right)^{2}=a^{2}b^{2} [/tex]


  5. May 14, 2005 #4
    what happens to the pi on top?
  6. May 14, 2005 #5
    It cancels with one of the pi's on the bottom.

    [tex]\frac{\pi y^2} {4\pi^2} = \frac{\pi y^2} {4\pi*\pi} = \frac{\pi(y^2)}{\pi(4\pi)}[/tex]

    Do you see how you can cancel?
  7. May 14, 2005 #6
    Yes Thanks
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