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Intercept question (manipulating equations)

  1. Jan 26, 2006 #1
    I saw this question yesterday.

    Find the x and y intercepts of:

    1/x = 1/y

    In this case are the intercepts undefined? Or can I cross multiply and get x = y, and then the intercepts are 0 and 0? Also, if I cannot cross multiply, or maniuplate the equation, does that mean that anytime you are not allowed to have x = 0, or y = 0 as values in the original equation, then the respective intercept is undefined?

  2. jcsd
  3. Jan 26, 2006 #2


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    Homework Helper

    The curve defined by that equation is the line y=x minus the point at the origin, so it has no intercepts. The equality simply doesn't hold (since the equation isn't well defined) at x=y=0.
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