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24-Ruby IV
ValeryOchkov24-Ruby IV
24-Ruby IV
January 26, 2019
Solved

Quadratic equation and a lsolve function

  • January 26, 2019
  • 4 replies
  • 4242 views

There is a quadratic algebraic equation. Is it possible, according to its coefficients a, b, and c, to form a system of two linear algebraic equations with the same roots as the quadratic equation?

Others word! Can I use the lsolve function for the solving a quadratic algebraic equation?

Best answer by Werner_E

Equally unfair but a little bit nicer

B.png

4 replies

F
Fred_Kohlhepp23-Emerald I
23-Emerald I
January 26, 2019

I used to work with older (back then) engineers who were adept at EXCEL and adverse to Mathcad,  We could get curve fits to polynomials by "creating" a column with the values for the other powers and using the EXCEL function "linest".  A similar trick should work for lsolve; that trick used in a least square matrix solver in Prime 4 is attached.

    L
    LucMeekes23-Emerald IV
    23-Emerald IV
    January 26, 2019

    Nice exercise Fred, but I don't see it solve the quadratic, or am I missing something?

     

    Luc

    L
    LucMeekes23-Emerald IV
    23-Emerald IV
    January 26, 2019

    I'm afraid not, Valery:

    LM_20190126_Quadratic.png

    Success!
    Luc

    V
    24-Ruby IV
    ValeryOchkov24-Ruby IVAuthor
    24-Ruby IV
    January 26, 2019

    I use the lsolve function for the solving a quadratic algebraic equation?

    Yes, we can! Smiley LOL

    lsolve-qe.png

     

    W
    Werner_E25-Diamond IAnswer
    25-Diamond I
    January 26, 2019

    Equally unfair but a little bit nicer

    B.png

      I
      IhorHuzar1-Visitor
      1-Visitor
      January 28, 2019

      Здравствуйте. Решал задачу в mathCad: методом наименьших квадратов рассчитать коэффициенты уравнения по результатам решения показаного в таблице полного двохуровневого трьохфакторного плана ПФЕ. Праподаватель сказал что есть ошибки, больше ничего не сказал, поможете?

      V
      24-Ruby IV
      ValeryOchkov24-Ruby IVAuthor
      24-Ruby IV
      January 29, 2019

      I think it will be better to write your question in English and put it here as new message!

      And better to have comments in your Mathcad-sheet in English!

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