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Homework Help: Parametric equation question

  1. May 23, 2010 #1
    1. The problem statement, all variables and given/known data

    Find an equation y=f(x) for the parametric curve x = cos (theta) y = cos (theta) + sin^(2) (theta)

    2. Relevant equations

    3. The attempt at a solution
    I know I need to solve for theta but I'm not sure how to go about this. Can I plug x into the theta's in y or do I use the trig identity sin^(2) + cos^(2) = 1? Thanks in advance!
  2. jcsd
  3. May 23, 2010 #2


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    Homework Helper
    Gold Member

    Use the fact that [itex]\cos\theta=x[/itex] and [itex]\sin^2\theta=1-\cos^2\theta[/itex].
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