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Confusion about ellipses

  1. Nov 2, 2011 #1
    This is a really dumb question, but could someone quickly explain why it is that if b > a in the equation of an ellipse then y is the major axis. Just intuitively I want to think that y^2/5 as opposed to y^2/3 is going to be smaller for a given value of y since each value is being limited by the dividend. The opposite is true. Can someone explain this simply?
  2. jcsd
  3. Nov 2, 2011 #2

    The distance [itex]r[/itex] of every point of the ellipses from the centre of the frame of reference is always between [itex]min(a,b)\leq r\leq max(a,b)[/itex].
    By definition, the major axis is defined as [itex]max(a,b)[/itex] while the minor axis is [itex]min(a,b)[/itex].
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