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Cubic Equation

  1. Nov 1, 2005 #1
    Hai, I have a question solving a cubic equation. I have a function
    y=ax*x*x+bx*x. I want to get a solution for the value of a and b. From reference, I found that a=(xtan(Theta)-2y)/(x*x*x) and
    [Theta] is an angle or tangent of each point x along a cubic curve or function. Could anyone guide me on how to prove this statement mathematically?
  2. jcsd
  3. Nov 1, 2005 #2


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    You want to solve for a and b but you didn't provide any conditions on them.
  4. Nov 2, 2005 #3


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    It is not at all clear what you want to do. Find values of a and b so that y= ax3+ bx2 has what properties??
  5. Nov 3, 2005 #4
    Well, anyway, from what you are saying, if we can choose values of X, just let X=1, giving Y=a+b. Then use a second value. Tangent of Theta? It might help to find out what that is.
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