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Homework Help: Parametric equations

  1. Sep 18, 2007 #1
    i have a couple questions that confuse me that would help me on doing my homework on parametric equations....

    do the parametric equations x=t^2 and y=t^2 describe the line y=x?
    and if y is a function of t and x is a function of t, then is y a funcion of x?
    and last, does x=cos t, y=cos^2(t) describe the parabola y=x^2?

    these arent my homework questions, but any help or explanation of this would really help me out...thanks : )
  2. jcsd
  3. Sep 18, 2007 #2


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    The first question: Yes;
    the second question: No.

    The cosine function restricts what values x and y can be. Cosine can only be between -1 and +1.

    You want to represent your y function as (cos(t))^2 unless you know how to use proper typesetting, such as TEX or something.,
  4. Sep 18, 2007 #3
    oh okay thanks a lot...so then to the last question though, the answer would be no? im just making sure....
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