Questions tagged [symmetric-polynomials]

Questions on symmetric polynomials, polynomials in several variables that are invariant under permutation of the variables.

A symmetric polynomial is a polynomial in several variables which is not changed after any permutation of variables. An important result about symmetric polynomials is the possibility to express any symmetric polynomial using elementary symmetric polynomials. Symmetric polynomials are useful, e.g., in connection with roots of polynomials (Vieta formulae). Another useful result concerns the Newton-Girard formulae, which expresses power sums in terms of elementary symmetric polynomials.

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Calculate $x^4 + y^4 + z^4$ if $x + y + z = 1$ , $x^2 + y^2 + z^2 = 2$ and $x^3 + y^3 + z^3 = 3$

I saw this problem here https://www.youtube.com/watch?v=4FNCIYD8HdA. Can anybody explain why I am getting different results using the following method. Notations: S(x4) = sum of all terms (each having coefficient 1) consisting of only one variable…
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Extension of Newton-Girard to matrix-indexed monomials

The Newton-Girard recursions evidently give a fast algorithm for computing the elementary symmetric polynomials $e_d(x_1,\ldots,x_n):=\sum_{1\leq k_1<\cdots
MathManM
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A way to read off $\deg \phi(P)$ directly from $P$ where $\phi:\mathbb{C}[x_1, \cdots, x_n]^{\mathfrak{S}_n}\to \mathbb{C}[e_1, \cdots, e_n]$?

Let $P(x_1, \cdots, x_n)\in \mathbb{C}[x_1, \cdots, x_n]^{\mathfrak{S}_n}$ be a symmetric polynomial and $Q(e_1, \cdots, e_n)$ be its image under the isomorphism $\mathbb{C}[x_1, \cdots, x_n]^{\mathfrak{S}_n}\to \mathbb{C}[e_1, \cdots, e_n]$ where…
Hamed
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Algorithm for writing a symmetric polynomial P(x,y) in terms of x+y and xy

Assume I am given a polynomial of two variables by the list of its coefficients, $P(X,Y)=\sum_{i,j}C_{ij}X^i Y^j$, and that this polynomial is symmetric, i.e. $C_{ij}=C_{ji}$. I am looking for an efficient algorithm for rewriting this polynomial on…
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Is every polynomial of two variables separable into a symmetric and antisymmetric part?

How can I split a polynomial into parts which are symmetric and antisymmetric under exchange of the variables? I have an explicit polynomial, which is a function of two variables (and some further constants). In the following image you can see the…
Thomas
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How to solve this equation with symmetric polynomials?

Here is what I did $$x + \sqrt {17 - x^2} + x\times\sqrt{17 - x^2} = 9$$ I can`t undestand how to solve it, any help would be appreciated!
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