1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Cubic Equation Cardano solution

  1. Jul 25, 2007 #1
    1. The problem statement, all variables and given/known data
    To solve the following equation
    3x^3 + x^2 + 15x + 27 = 0

    2. Relevant equations



    3. The attempt at a solution

    {(x-> 1/9{-1 - 134/(-3079+27Sqrt.(16305)^(1/2) + (-3079+27Sqrt.(16305)^(1/3)}

    {x-> -1/9 + 67(1+iSqrt.3)/9(-3079+27Sqrt.(16305)^(1/2) -1/18 (1-iSqrt.3)(-3079+27Sqrt.(16305)^(1/2)}

    Is this correct ?

    {x-> -1/9 + 67(1-iSqrt.3)/9(-3079+27Sqrt.(16305)^(1/2) - 1/18 (1+iSqrt.3)(-3079+27Sqrt.(16305)^(1/2)}
     
  2. jcsd
  3. Jul 25, 2007 #2
    I actually mastered the cubic solution.
    I used this site.
    The methods of Cardano/Tartaglia are trully beautifully derived.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook