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R=2cosθ Convert to rectangular form?

  1. Oct 2, 2011 #1
    It does not explain it in any of the books ? So no clue even on how to start other than,
    R = X squared + Y squared
  2. jcsd
  3. Oct 2, 2011 #2


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    Homework Helper

    First of all this isn't correct. It should be
    r2 = x2 + y2.

    Second, if you have a textbook, check it again, because there are at least two other equations that can be used to convert polar equations:
    x = r cos θ and y = r sin θ.

    As for your problem,
    r = 2 cos θ,
    start by multiplying both sides by r. Then substitute.
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