Polynomials are expressions like $15x^3 - 14x^2 + 8$. Questions tagged with this concern common operations on polynomials, like adding, multiplying, polynomial long division, factoring and solving for roots.

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How to evaluate real root of a polynomial equation? [closed]

If $\alpha$ is a real root of the polynomial equation $$300x^{299}+299x^4+343x^3+23x+300=0$$ Then how to find out the value of $[\alpha]\space $ where, '$[ \space]$' denotes greatest integer? I have ...
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Regular Subresultant PRS from Euclidean PRS?

Is there any way to compute regular subresultant polynomial remainder sequence if we know the Euclidean polynomial remainder sequence of two univariate polynomials and vice versa?
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Does the inverse of a polynomial matrix have polynomial growth?

Let $M : \mathbb{R}^n \to \mathbb{R}^{n \times n}$ be a matrix-valued function whose entries $m_{ij}(x_1, \dots, x_n)$ are all multivariate polynomials with real coefficients. Suppose that ...
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Polynomials and Euclidean algorithm

I have the next problem. Determine the gcd $d(x)$ of two polynomials with real coefficients $a(x) = x^{4}-1$ and $b(x) = x^{3}-x^{2}-x+1$. And then, determine two polynomials with real coefficients ...
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Ideal generated by two polynomials

Let a sequence of polynomials $\{f_n\}_{n=0}^\infty$ in $\mathbb{Q}[x,y]$ be given in the following way: $$f_0=1,$$ $$f_1=-x,$$ $$f_2=x^2-y,$$ $$f_{n+2}=-xf_{n+1}-yf_n.$$ For each $n\geq 0$, find ...
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dimension of quotient by algebraically independent elements

Let $f_1,\dots,f_s$ be algebraically independent polynomials of $A:=k[x_1,\dots,x_n]$, $s \le n$. Recall that algebraically independent means that there is no non-zero polynomial $g \in ...
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Algebraic independence via the Jacobian

I have seen being mentioned that algebraic independence of polynomials can be tested by the so called Jacobian Criterion (Apparently one takes the Jacobian matrix of these polynomials and inspects the ...
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Degree of minimum polynomial at most n without Cayley-Hamilton?

Let $T$ be a linear transformation of an $n$-dimensional vector space $V$ over a field $k$. It's pretty easy to define the minimum polynomial of $T$ and make sure its degree is between $1$ and $n^2$, ...
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Why are the Hermite Polynomials important?

I know a lot about the properties of the polynomials, but I don't know for what purpose they were developed or why they continue to be studies. Why are Orthogonal polynomials important besides their ...
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How can I prove the polynomial f is irreducible

We have $f\in \mathbb{Z}_{3}\left[X\right],\:\:f=x^3+2x^2+a,\:\:a\in \mathbb{Z}_{3}$ and we need to find $a$ for which polynomial $f$ is irreducible. I looked on google but I don't understand very ...
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Polynomial Factorisation - Linear Algebra

Im attempting a linear algebra question in which I have been given the following quadratic form $q(x,y,z) = x^2+25y^2+10xy+2yz$. I have to find a basis $B$ such that $[f]_B$ has the real canonical ...
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Area & order-preserving function transformations

Consider a bounded function $f(x \in \mathbf{R}) \rightarrow \mathbf{R}$ with bounded support $\left[0,L\right]$ (illustration below). What type of transformations $g(f(x))$ guarantee that: Area ...
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Is $\int_{\mathbb R} f(\sum_{k=1}^n\frac{1}{x-x_k})dx$ independent of $x_k$'s for certain $f$?

My question below arises from the linked question $ \int\limits_{-\infty}^{+\infty}\frac{(p'(x))^2}{(p'(x))^2+(p(x))^2}\,dx \leq n^{3/2}\pi$ and the comments by jack and David Speyer under that ...
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Polynomials - finding the remainder

Find the remainder when $x^{51} + 51$ is divided by $x-a$. The given answer is 50 but am not reaching it. Please help, with suitable explanation.
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Automorphism of $\Bbb Q[x]$

Question: Find a nonidentity automorphism $\varphi$ of $\Bbb Q[x]$ such that $\varphi^2$ is the identity automorphism of $\Bbb Q[x]$. Is $\varphi(\Bbb Q[x]) = \Bbb Q[-x]$ a solution? I think it ...
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Why would I divide these two equations to solve for i?

I have the following two equations representing a longer actuarial practice question. I properly set up the equations, but am stumped on how to solve them. The book says to divide the first by the ...
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Fitting a polynomial with arbitrary derivative values

Given two points $(x_1, y_1)$ and $(x_2, y_2)$ with $x_2 > x_1$ and $y_2 < y_1$, I can obviously fit a line (order $1$ polynomial) to them. But if I want to fit a quadratic function by ...
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Can every continuous function on complex domain be approximated by polynomials pointwise?

Do you know any theorem that will help me with this question: Let $f$ be any continuous function on complex plane. Show that there is a sequence $(P_n)$ of polynomials such that $P_n$ converges ...
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How do I find a relation for these polynomials from a matrix?

I have the following three polynomials: $1 + 2t^2, 4 + t + 5t^2, 3 + 2t$. I need to show that they are linearly dependent in $\mathbb P_2$ (polynomials of degree at most $2$). I put them in a $3x3$ ...
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Determine if a given set of vectors span $\mathbb{R}[x]_{\leq2}$

I am working on a linear algebra question, which asks you to determine if the vectors $(1+x), (1-x), x, (1+x^2)$ span the vector space $V=\mathbb{R}[x]_{\leq2}$. I think that the four vectors do ...
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A cheap error estimate and a costly doubt

Carl de Boor poses the following problem in his A Practical Guide to Splines (1978 - Chapter II, p. 38, problem 4): The calculation of $||g|| = \max\{|g(x)| : a \le x \le b\}$ is a nontrivial ...
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Why is the degree condition for a degree reverse lexicographic order necessary?

A degree reverse lexicographic order $\prec$ is defined as follows: Given the polynomial ring $R=K[x_1,...,x_n]$. Two monomials in $R$ have the order $x^u\prec x^v$, if $\deg(x^u)<\deg(x^v)$, or ...
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Limits of Taylor POlynomials over $k$-tuples?

Let $f \in \mathscr{C}^{(m)}(E),$ where $E$ is an open subset of $R^{n}$. Fix $\textbf{a}$ $\in E$, and suppose $\textbf{x}$ $\in R^{n}$ is so close to $\textbf{0}$ that the points \begin{equation*} ...
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Long division for multipolynomial expression, little o notation

I have this expression: $$\mathrm{Exp}=\frac{d^3(-12a^4)+d^2(4a^4-16a^3)+d(4a^3-6a^2-a)}{d^3(-12a^4+12a^3)+d^2(4a^4-20a^3+16a^2)+d(4a^3-11a+7a)+(1-2a+a^2)}$$ Is there any way I can take the second ...
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How to calculate the sum $\sum_{i=0}^\infty i^nx^i$ [duplicate]

Here I have $x\in\mathbb{R}_+$ and $x < 1$. I would like to evaluate the following sum: $$\sum_{i=0}^\infty i^nx^i.$$ I know that $$\sum_{i=0}^\infty x^i=\dfrac{1}{1-x}.$$ So I started ...
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What is an irreducible polynomial in $\mathbb{Z}$ that has root $\sqrt{2}+\sqrt{3}$?

What is an irreducible polynomial in $\mathbb{Z}$ that has root $\sqrt{2}+\sqrt{3}$? Obviously that root is not in $\mathbb{Z}$. I tried ...
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Ring Homomorphism Textbook Question

Please help me understand the last three sentences in this paragraph from the Artin textbook. Where does this come from: "The monomials that appear in $r_0(t^2)$ have even degree, while those in ...
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$T(M) \cong R<x_1,\ldots,x_n>$ isomorphism question

I have that $T(M) = \bigoplus_{i =1}^{\infty} T^i(M)$ where $T^k(M) = \bigotimes_{i =1}^{k} M$. In a paper i have that to prove such isomorphism, we define: $$\Phi:R<x_1, \ldots, x_n> ...
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$f(x)f(1/x)=f(x)+f(1/x)$

Find a function $f(x)$ such that: $$f(x)f(1/x)=f(x)+f(1/x)$$ with $f(4)=65$. I have tried to let $f(x)$ be a general polynomial: $$a_0+a_1x+a_2x^2+\ldots a_nx^n$$ which leaves $f(1/x)$ as: ...
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A quadratic polynomial bounded by another

Suppose $p(x)$ and $q(x)$ are two quadratic polynomials in real coefficients such that: $$\lvert p(x) \rvert \leq \lvert q(x) \rvert ~ ~ ~ \text{for all} ~ x \in \mathbb{R} \tag{1}$$ Is the above a ...
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What polynomial with real coefficients generates all polynomials with real coefficients that satisfies $f(2+i)=0$?

What polynomial with real coefficients generates all polynomials with real coefficients that satisfies $f(2+i)=0$? Obviously, the polynomial $f(x)=x-2-i$ satisfies the constraint but does not have ...
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$\left( 1 - \frac{1}{n} \right)\left( 1 - \frac{2}{n} \right) \cdot … \cdot \left( 1 - \frac{k-1}{n} \right) = \frac{n!}{n^k r! (n-k-r)!}$

I'm trying to understand a proof in "Interpolation and Approximation by Polynomials" by Phillips. Let me quote (page 253): "For $k\geq 1$ we begin with $$B_{n+k}^{(k)}(f;x)=\frac{(n+k)!}{n!} ...
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ideals of polynomial ring with complex number coefficients

Let $\mathbb{C}[x,y]$ be the polynomial ring with variables $x,y$ and coefficient in $\mathbb{C}$. Let $f,g\in \mathbb{C}[x,y]$. Let $(f,g)$ be the ideal of $\mathbb{C}[x,y]$ generated by $f,g$. ...
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Find the remainder when $x^{100} + 2x + 10$ is divided by $x − 11$ in $\mathbb Z_{17}[x]$

Find the remainder when $x^{100} + 2x + 10$ is divided by $x − 11$ in $\mathbb Z_{17}[x]$ I simplified $x^{100} + 2x + 10$ to $x^{15} + 2x + 10$ and $x − 11$ to $x+6$ to be in $\mathbb Z_{17}$. ...
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About polynomials. If there are no two polynomials of the same degree in $S$, then $S$ is linearly independent.

The problem states as follows. Let $S$ be a set of non-zero polynomials over a field$ F$. If there are no two pplynomials of the same degree in $S$, then $S$ is linearly independent. I tried the ...
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Ring polynomial kernel generators

This is the textbook question: Q: Find generators for the kernels of the following maps: $\mathbb{R}[x,y] \to \mathbb{R}$ defined by $f(x,y) \mapsto f(0,0)$ $\mathbb{R}[x] \to \mathbb{C}$ defined ...
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Is it possible to find the value of $x$ where $e^x$ exceeds $x^{10}$ by hand?

All I managed is to "simplify" the equation $e^x=x^{10}$ to $\frac{x}{\ln{x}}=10$. Is there some way or trick to make the equation look like $x=\dots$? (Solve the equation, in other words.)
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Solving an equation with complex numbers

I want to use complex numbers to solve the following problem: $x^2 = 95 - 168i$. I am sure there are a few ways of doing this but the way I want to do it is to let $x = a + bi$ and then solve for $a$ ...
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Find the least degree Polynomial whose one of the roots is $ \cos(12^{\circ})$

Find the least degree Polynomial with Integer Coefficients whose one of the roots is $ \cos(12^{\circ})$ My Try: we know that $$\cos(5x)=\cos^5x-10\cos^3x\sin^2x+5\cos x\sin^4x$$ Putting ...
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Symmetric functions and roots of polynomials

$f = x^3-\frac{1}{2}x^2+1$ and their roots $a,b,c$. I want to find polynomial of degree 3 with roots $a^4,b^4,c^4$. I know that i need express $e_i(a^4,b^4,c^4)$ in terms of $e_i(a,b,c)$ those ...
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How can I maintain notes while self studying Maths?

Thank you for stopping by this thread. I'm an engineering student rekindling an interest in Maths. I just love studying Maths in my free time (and sometimes it trespasses into my non free time). I ...
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Finding roots in finite fields.

On pg. 587 (in the finite fields chapter) of Abstract Algebra, 3rd ed. by Dummit and Foote, the following statement is made: 'If $f_1(x)=x^4+x^3+1$, $f_2(x)=x^4+x+1$ are two of the irreducible ...
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Discriminant of a polynomial modulo a prime

If $p$ is a prime and divides the discriminant of an irreducible polynomial $f(x)=x^{n}+a_{n-1}x^{n-1}+\cdots+a_1x+a_0\in \mathbb{Z}[x]$ why is then $disc(f(x)\bmod p)=0$? I know that the ...
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When can I divide both sides of an equation if one side is zero

Where K is some positive Integer For the following examples: $$ K(a+b)(p+q)=0 $$ $$ Ka^2+Kbx+Kc=0 $$ Can I just divide both sides of the equation by K (dividing into 0 on the right) and effectively ...
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Show that $B^{(1)} = 0$ and $B^{(2)}$ have basis $\{[x_i,x_j]; i>j\}$

Definition: A polynomial $f \in K \langle X \rangle$ is called a proper polynomial, if it is a linear combination of products of commutators: $$f(x_1,x_2,...x_n) = \sum ...
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$\mathbb Q [\sqrt{2} i]$ contains neither $\sqrt[4]{2}$ nor $\sqrt{2}$

I want to prove that $x^4-2$ is irreducible over $\mathbb Q [\sqrt{2} i]$. In order to verify it has no linear factors and quadratic factors, I need to show $\mathbb Q [\sqrt{2} i]$ contains neither ...
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can I draw a 2nd degree 2 dimensional surface trough 3x3 points, like I can draw a 2nd degree polynomial through any 3 points

A Nth degree polynomial f(x) fitting N+1 points, say at regular distances like x = 1,2,3,4,5,... can be used conveniently to interpolate for values of x in between the given ones. I have a set of ...
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Solving the functional equation $f(x^2+f(y))=(f(x))^2+y$

Find all $ f : R\rightarrow R $ such that $f(x^2+f(y))=(f(x))^2+y, \forall\text{ x,y}\in R$ Thanks in advance!
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Polynomial Equation Solution

Use Demoivre's theorem to show: $cos 7θ = 64 cos7 θ − 112 cos5 θ + 56 cos3 θ − 7 cos θ$ Hence,solve: $128x^7 −224x^5 +112x^3 −14x+1=0$ I've shown the first part and multiplied the equation by 2 and ...
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What sequence of polynomials is equal to $2^n$ for integers $1$ to $k$?

I am trying to prove to someone that no matter how many terms you have of a sequence you can never be 100% sure of the underlying formula. Consider this sequence: $$2^n=1,2,4,8,16,...$$ But just given ...