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Homework Help: Graph of a cardiod

  1. Feb 15, 2012 #1
    1. The problem statement, all variables and given/known data


    3. The attempt at a solution

    I don't see how they get

    1 - cos (pi/3) = 1/2

    cos (pi/3) = √3/2

    1 - √3/2 = .14, not .5 like the book says

    for the other figures I agree with the book.
  2. jcsd
  3. Feb 15, 2012 #2


    Staff: Mentor

    What's not to get? cos([itex]\pi[/itex]/3) = 1/2.

    You need to brush up on your trig.
    No, this is not true. sin([itex]\pi[/itex]/3) = √3/2.
  4. Feb 15, 2012 #3
    never mind, I was mixing pi/6 up with pi/3
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