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Coding Challenge for Vieta's Formulas
07-12-2018, 11:15 PM (This post was last modified: 07-13-2018 06:37 PM by Namir.)
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Coding Challenge for Vieta's Formulas
I am interested in coding general cases of the Vieta's formulas (check the Wikipedia article to see these formulas in a high-level language like VBA, Python, Matlab, and C++. The target is to have a function that sums up the squares of the LHS - RHS of each Vieta formula:

F(X,a) = (LHS1 - RHS1)^2 + (LHS2 - RHS2)^2 + ... + (LHSn - RHSn)^2

Where:

LHS1 = sum(X(i)) for i = 1 to n
RHS1 = - a(n-1)/a(n))

LHS2 = ((X(1)*X(2) + X(1)*X(3) + ... + X(1)*X(n)) +
((X(2)*X(3) + X(2)*X(4) + ... + X(2)*X(n)) +
... +
X(n-1)*X(n)
RHS2 = a(n-2)/a(n))
....
LHSn = product(X(i)) for i = 1 to n
RHSn = (-1)^n * a(0)/a(n)

The parameters are the array X() which represents the guesses for the roots, and array a() that represents the polynomial coefficients. The Wikipedia article designates a(n) as the coefficient for x^n and a(0) as the constant term.

Good luck to us all!!

Namir
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Coding Challenge for Vieta's Formulas - Namir - 07-12-2018 11:15 PM



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