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Homework Help: Ellipse Compression and Expansion

  1. Apr 22, 2005 #1
    An ellipse is defined by the equation [tex] \frac {x^2}{144} + \frac {y^2}{36} = 1[/tex]. Determine the equation of the ellipse formed when the original ellipse has undergone a horizontal compression by a factor of 1/2 and a vertical expansion by a factor of 3.

    I'm not quite sure how to work out the equation.. could someone give me some hints?
  2. jcsd
  3. Apr 22, 2005 #2

    Doc Al

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    Staff: Mentor

    You need to recognize the standard form for the equation of an ellipse:
    [tex] \frac {x^2}{a^2} + \frac {y^2}{b^2} = 1[/tex]

    That's the equation for an ellipse centered at the origin. The length of the horizontal axis is 2a; the vertical axis is 2b.
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