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Homework Help: Are these two functions equivalent when y = 0?

  1. Oct 28, 2011 #1
    Hello!

    Am I right to conclude that:
    [tex]y^2(A(\frac{x}{y})^2 + B(\frac{x}{y})+ C) = Ax^2 + Bxy + Cy^2[/tex]

    Only when y does not equal zero. I'm guessing I could evaluate the function lim y -> 0 but this is not the same as y explicitly equalling zero, is it? On the RHS, y can equal zero, on the LHS, y cannot equal zero. So I am guessing they are only equal when y does not equal zero.
    Is this true?

    Many thanks.
     
  2. jcsd
  3. Oct 28, 2011 #2
    Indeed, you cannot evaluate the expression in 0. It is undefined in 0.
     
  4. Oct 29, 2011 #3
    Thanks Micro!
     
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