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Coordinate Geometry

  1. Dec 16, 2006 #1
    1. The problem statement, all variables and given/known data
    Sketch the curves with the following equations:
    a) y=5x^(3/4)
    b) y=-2x^(-3/2)

    2. Relevant equations
    The general equation of curves (circles, parabola, ellipse, hyperbola)

    3. The attempt at a solution
    It seems to me that this question is not exactly a coordinate geometry question. At first, I thought this is a parametric equation, but parametric equation use t instead of y. Then, I thought of substituting x with some other things. But that fails as well. (The fraction power make it not rational to be substituted by x^2, x^3 and so on.) The equation doesn't resemble general equation circles, parabola, ellipse, or hyperbola.

    How should I attempt this question? Is equation of curves really useful to solve this question?
  2. jcsd
  3. Dec 16, 2006 #2


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    Homework Helper

    You are given two functions y(x). Start with finding their domains.
  4. Dec 16, 2006 #3
    There are other basic graphs of functions, so these would be some of them. Perahps it would be easier for you to re-write the fractional exponents. Well, that would be if you have gotten to that (or know how to).

    I will let you know though, both of those equations don't resemble a circle, parabola, ellipse, or hyperbola.

    As I said, try manipulating the exponents.
  5. Dec 21, 2006 #4


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    Science Advisor

    As pointed out, these are not quadratic functions and so their graphs are not conic-sections (circle, ellipse, hyperbola, parabola). Basically, just calculate y for a number of x values and draw a smooth curve through the points. As radou said, you'd better check the domains.
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