How to Solve This Cubic Equation Turned Out to Be A Special Case of Differences of Cubes and Squares

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  • Опубліковано 14 лис 2024

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  • @rfarrelldic
    @rfarrelldic 2 місяці тому +1

    very nice video well represented and well explained. Thank you. But this method only works if the constant can be decomposed into thw replacement cube and square term as required,

  • @rfarrelldic
    @rfarrelldic 2 місяці тому +1

    Very arreactuve and well explained. Thank you. But this mergid we only work if the constant can be decomposed into the two cubes required

  • @marlydahl
    @marlydahl Рік тому +1

    This can be easily solved using synthetic division but you took it to a whole 'nother level. Very nice tips and tricks.

    • @learnmathbydoing
      @learnmathbydoing  Рік тому

      Yes po, you are right. We just use this as an opportunity to share another method they can use in solving this problem

  • @nasrullahhusnan2289
    @nasrullahhusnan2289 6 місяців тому +2

    By inspection x³+x²=12 can be written as x³+x²=2³+2². Hence x=2.
    To find other root, if any, note that the last equation can be written as
    x³-2³+x²-2²=0
    (x-2)(x²+2x+4)+(x+2)(x-2)=0
    (x-2)(x²+3x+4)=0
    x=2, x=½[-6±isqrt(3)]
    For real root x=2 is the only one. Other root is a complex one.