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Homework Help: Horizontal tangent problem

  1. Jan 11, 2009 #1
    1. The problem statement, all variables and given/known data

    4x - 2xy = 0
    how do i solve for EITHER x or y?

    2. Relevant equations



    3. The attempt at a solution

    i got y = 2 at first but when i plugged it into the original equation to find x it was impossible to get an answer (the x's cancelled out)
     
  2. jcsd
  3. Jan 11, 2009 #2

    rock.freak667

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    Homework Helper

    the x doesn't cancel out.

    4x-2xy=0
    2x(2-y)=0

    so 2x=0 or 2-y=0.

    Meaning x=0,y=2
     
  4. Jan 11, 2009 #3
    the original equation is 2y^3 + 6(x^2)y - 12x^2 + 6y = 1
     
  5. Jan 11, 2009 #4
    4x-2xy=0
    4x=2xy
    4=2y
    2=y
    4x-2x(2)=0
    4x=2x(2)
    4x=4x
    x=1
    4(1)-2(1)(2)
    4-4=0
    yeah i think thats right but not 100% sure
     
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