Polynomial Definition and 1000 Threads

  1. Fantini

    MHB Legendre Polynomial and Legendre Equation

    Given $f(x) = (x^2-1)^l$ we know it satisfies the ordinary differential equation $$(x^2-1)f'(x) -2lx f(x) = 0.$$ The book defines the Legendre polynomial $P_l(x)$ on $\mathbb{R}$ by Rodrigues's formula $$P_l(x) = \frac{1}{2^l l!} \left( \frac{d}{dx} \right)^l (x^2-1)^l.$$ I'm asked to prove by...
  2. MisterH

    Curve extrapolation: polynomial or Bézier?

    On a stationary, non-periodic signal (black) a smooth causal filter is calculated (green/red). It is sampled discretely (every distance unit of 1 on the X-axis). My goal is to find which "path" it is "travelling" on so I can extrapolate the current shape until it is completed (reaches a...
  3. K

    MHB Find Min Polynomial of $\alpha$ Over $\mathbb{Q} | Solution Included

    I started by setting $\alpha= e^{2\pi i/3} + \sqrt[3]{2}.$ Then I obtained $f(x) = x^9 - 9x^6 - 27x^3 - 27$ has $\alpha$ as a root. How can I proceed to find the minimal polynomial of $\alpha$ over $\mathbb{Q},$ and identify its other roots?
  4. N

    Complex Polynomial of nth degree

    Homework Statement Show that if P(z)=a_0+a_1z+\cdots+a_nz^n is a polynomial of degree n where n\geq1 then there exists some positive number R such that |P(z)|>\frac{|a_n||z|^n}{2} for each value of z such that |z|>R Homework Equations Not sure. The Attempt at a Solution I've tried dividing...
  5. C

    Critical points and of polynomial functions

    Homework Statement A rectangular region of 125,000 sq ft is fenced off. A type of fencing costing $20 per foot was used along the back and front of the region. A fence costing $10 per foot was used for the other sides. What were the dimensions of the region that minimized the cost of the...
  6. E

    MHB Find the minimal polynomial of some value a over Q

    I'm trying find the minimal polynomial of $$a=3^{1/3}+9^{1/3}$$ over the rational numbers. I am currently going about this by trying to construct a polynomial from a (using what I intuitively feel would be a sufficiently small number of operations). Then I'd show it's irreducible by decomposing...
  7. N

    MHB Can a Non-Integer Exponent be Used to Solve a Polynomial Equation?

    Not sure if this is the right place but could somebody help me solve the following equation B.x^b - x - A =0 wher A, B and b are constants. Thanks
  8. D

    Confirm Degree & Dominant Term of Polynomial Equation

    Can someone just confirm my answers to this easy polynomial question, State the degree and dominant term to f(x)=2x(x-3)^3(x-1)(4x-2) I am working on this online and there is nothing on working on equations like this in the lesson. I believe the degree to be either 2 or 6, as the functions end...
  9. M

    Orthogonality of Associated Laguerre Polynomial

    I have a problem when trying to proof orthogonality of associated Laguerre polynomial. I substitute Rodrigue's form of associated Laguerre polynomial : to mutual orthogonality equation : and set, first for and second for . But after some step, I get trouble with this stuff : I've...
  10. evinda

    MHB Two different algorithms for valuation of polynomial

    Hello! (Wave) The following part of code implements the Horner's method for the valuation of a polynomial. $$q(x)=\sum_{i=0}^m a_i x^i=a_0+x(a_1+x(a_2+ \dots + x(a_{m-1}+xa_m) \dots ))$$ where the coefficients $a_0, a_1, \dots , a_m$ and a value of $x$ are given: 1.k<-0 2.j<-m 3.while...
  11. T

    Estimate number of terms needed for taylor polynomial

    Homework Statement For ln(.8) estimate the number of terms needed in a Taylor polynomial to guarantee an accuracy of 10^-10 using the Taylor inequality theorem. Homework Equations |Rn(x)|<[M(|x-a|)^n+1]/(n+1)! for |x-a|<d. The Attempt at a Solution All I've done so far is take a couple...
  12. B

    Polynomial fractions simplest form?

    I was taught that when you have a polynomial fraction where the denominator is of a higher degree than the numerator, it can't be reduced any further. This seems wrong to me for a couple of reasons. 1. If the denominator can be factored some of the terms may cancel out 2. Say you have the...
  13. I

    Understanding square root of a polynomial

    Hello This is not exactly a homework problem. I was browsing through an old book, "Elementary Algebra for Schools" by Hall and Knight, first published in England in 1885. The book can be found online at https://archive.org/details/elementaryalgeb00kniggoog . I was studying the process of...
  14. anemone

    MHB Polynomial Challenge: Show $f(5y^2)=P(y)Q(y)$

    Given that $f(x)=x^4+x^3+x^2+x+1$. Show that there exist polynomials $P(y)$ and $Q(y)$ of positive degrees, with integer coefficients, such that $f(5y^2)=P(y)\cdot Q(y)$ for all $y$.
  15. PsychonautQQ

    Finding inverse in polynomial factor ring

    Homework Statement find the inverse of r in R = F[x]/<h>. r = 1 + t - t^2 F = Z_7 (integers modulo 7), h = x^3 + x^2 -1 Homework Equations None The Attempt at a Solution The polynomial on bottom is of degree 3, so R will look like: R = {a + bt + ct^2 | a,b,c are elements of z_7 and x^3 = 1 -...
  16. M

    Polynomial Long Division for Limit Calculation

    Homework Statement \frac{x^5-a^5}{x^2-a^2}, where a is some constant. Homework EquationsThe Attempt at a Solution I can't figure out how to do this with long division. With synthetic, I can get to \frac{a^4+a^3 x+a^2 x^2+a x^3+x^4}{a+x} x^3+xa^2+...
  17. anemone

    MHB Solving Cubic Polynomial: Prove Two Distinct Roots

    Let $p,\,q,\,r,\,s,\,t$ be any real numbers and $s\ne 0$. Prove that the equation $x^3+(p+q+r)x^2+(pq+qr+rp-s^2)x+t=0$ has at least two distinct roots.
  18. anemone

    MHB Challenge for Polynomial with Complex Coefficients

    Let $ax^2+bx+c$ be a quadratic polynomial with complex coefficients such that $a$ and $b$ are non-zero. Prove that the roots of this quadratic polynomial lie in the region $|x|\le\left|\dfrac{b}{a}\right|+\left|\dfrac{c}{b}\right|$.
  19. 22990atinesh

    Highest degree of a given polynomial is

    Homework Statement A polynomial p(x) is such that p(0)=5, p(1)=4, p(2)=9 and p(3)=20. the minimum degree it can have a) 1 b) 2 c) 3 d) 4 Homework EquationsThe Attempt at a Solution a) Not Possible can't connect these points using straight line b) Not even possible to connect these points using...
  20. R

    Real Solutions of 4th Degree Polynomial Equation

    Homework Statement To find number of real solutions of: ##\frac{1}{x-1}## ##+\frac{1}{x-2}## + ##\frac{1}{x-3}## + ##\frac{1}{x-4}## =2[/B] Homework Equations It will form a 4th degree polynomial equation. The Attempt at a Solution The real solutions could be 0 or 2 or 4 as complex...
  21. anemone

    MHB Is the Remainder of Polynomial $f(x)$ the Same for Two Different Divisors?

    Show that the remainder of the polynomial $f(x)=2008+2007x+2006x^2+\cdots+3x^{2005}+2x^{2006}+x^{2007}$ is the same upon division by $x(x+1)$ as upon division by $x(x+1)^2$.
  22. I

    Factoring a third degree polynomial

    Homework Statement Factor out the polynomial and find its solutions x^3-5x^2+7x-12[/B]Homework EquationsThe Attempt at a Solution I tried to factor it, but I'm stuck in this step x^2(x-5)+7(x-5)+23= 0. I graphed the equation, and I know there is two imaginary solutions and one real positive...
  23. evinda

    MHB Showing $XF_{X}+YF_{Y}+ZF_{Z}=nF$ with a Homogeneous Polynomial

    Hi! (Smile) Let $F(X,Y,Z) \in \mathbb{C}[X,Y,Z]$ a homogeneous polynomial of degree $n$. Could you give me a hint how we could show the following? (Thinking) $$XF_{X}+YF_{Y}+ZF_{Z}=nF$$
  24. RJLiberator

    Evaluating the remainder of a Taylor Series Polynomial

    Homework Statement The goal of this problem is to approximate the value of ln 2. We will use two different approaches: (a) First, we use the Taylor polynomial pn(x) of the function f(x) = lnx centered at a = 1. Write the general expression for the nth Taylor polynomial pn(x) for f(x) = lnx...
  25. RJLiberator

    Basic Taylor Polynomial Question involving e^(-x)^2

    Homework Statement Consider:[/B] F(x) = \int_0^x e^{-x^2} \, dx Find the Taylor polynomial p3(x) for the function F(x) centered at a = 0. Homework Equations Tabulated Taylor polynomial value for standard e^x The Attempt at a Solution [/B] I started out by using the tabulated value for Taylor...
  26. anemone

    MHB Find the smallest possible degree of a polynomial

    Let $h(x)$ be a nonzero polynomial of degree less than 1992 having no non-constant factor in common with $x^3-x$. Let $\dfrac{d^{1992}}{dx^{1992}}\left(\dfrac{h(x)}{x^3-x}\right)=\dfrac{m(x)}{n(x)}$ for polynomials $m(x)$ and $n(x)$. Find the smallest possible degree of $m(x)$.
  27. MartinJH

    Integration of a polynomial problem

    Hi, I'm using KA Stroud 6th edition (for anyone with the same book, P407) and there is a example question where I just can't seem to get the answer they have suggested: Homework Statement [/B] Question: Determine the value of I = ∫(4x3-6x2-16x+4) dx when x = -2, given that at x = 3, I = -13...
  28. ch3cooh

    Polynomial approximation: Chebyshev and Legendre

    Chebyshev polynomials and Legendre polynomials are both orthogonal polynomials for determining the least square approximation of a function. Aren't they supposed to give the same result for a given function? I tried mathematica but the I didn't get the same answer :( Is this precision problem or...
  29. J

    I don't understand polynomial division

    At first he shows 2x+4 / 2 and you just divide both 2x and 4 by 2. But then in the next example he is dividing x^2+3x+6 by x+1 and he doesn't divide x^2 by x+1, 3x by x+1 and 6 by x+1. I do not understand how he does the problem.
  30. T

    Taylor Polynomial of 3rd order in 0 to f(x) = sin(arctan (x))

    The problem is as the title says. This is an example we went through during the lecture and therefore I have the solution. However there is a particular step in the solution which I do not understand. Using the Taylor series we will write sin(x) as: sin(x) = x - (x^3)/6 + (x^5)B(x) and...
  31. M

    MHB The polynomial is irreducible iff the condition is satisfied

    Hey! :o I need some help at the following exercise: Show that the polynomial $f(x)=x^n+1 \in \mathbb{Q}[x]$ is irreducible if and only if $n=2^k$ for some integer $k \geq 0$. Could you give me some hints what I could do?? (Wondering)
  32. C

    Find the constant polynomial g closest to f

    Homework Statement In the real linear space C(1, 3) with inner product (f,g) = integral (1 to 3) f(x)g(x)dx, let f(x) = 1/x and show that the constant polynomial g nearest to f is g = (1/2)log3. Homework EquationsThe Attempt at a Solution I seem to be able to get g = log 3 but I do not know...
  33. E

    MHB Solving Polynomial Inequalities

    Solve the following inequality: 6e) $(x - 3)(x + 1) + (x - 3)(x + 2) \ge 0$ So, I created an interval table with the zeros x-3, x+1, x-3 and x+2 but I keep getting the wrong answer. Could someone help? (this is grade 12 math - so please don't be too complicated). Thanks.
  34. C

    Transform 10 to 1000 Points on x^9 to x^2 Polynomial

    In the above title 10 and 1000 are arbitrary numbers I will use them below to signify the concept of a smaller and larger number. I know that n points are described by at most an x^(n-1) polynomial. What I really mean to ask is: Is it possible to take a "smaller" amount of points say 10, go...
  35. M

    How Do You Formulate a Polynomial for Volume in This Prism Problem?

    Homework Statement A package sent by a courier has the shape of a square prism. The sum of the length of the prism and the perimeter of its base is 100cm. Write a polynomial function to represent the volume V of the package in terms of x. width and height are in x centimeters, length is in y...
  36. datafiend

    MHB Find zeros of polynomial and factor it out, find the reals and complex numbers

    Hi all, $$f(x) = 3x^2+2x+10$$ I recognized that this a quadratic and used the quadratic formula. I came up with $$-1/3+-\sqrt{29}/3$$. But the answer has a $$i$$ for imaginary. When I was under the \sqrt{116}, I broke that down, but didn't realize there would be an $$i$$ Can someone explain...
  37. anemone

    MHB Find Polynomial Q(x): Remainder -1 & 1

    Determine a real polynomial $Q(x)$ of degree at most 5 which leaves remainders $-1$ and 1 upon division by $(x-1)^3$ and $(x+1)^3$ respectively.
  38. G

    How to find a polynomial from an algebraic number?

    Given some algebraic number, let's say, √2+√3+√5, or 2^(1/3)+√2, is there some way to find the polynomial that will give 0 when that number is substituted in? I know that there are methods to find the polynomial for some of the simpler numbers like √2+√3, but I have no clue where to begin for...
  39. datafiend

    MHB Determine if a function is a polynomial

    I'm going through polynomials and the the problem: $$g\left(x\right)= (4+x^3)/3 $$ IS NOT A POLYNOMIAL FUNCTION. I don't get it. The answer says $$x\ne0$$, it's not a polynomial. How did you deduce that? Going down the rabbit hole...and it's the third week.
  40. O

    MHB Can a polynomial ever just have 2 terms?

    Or does it always have to have MORE THAN 2 like x^2 +x^2 -4a polynomial can never be x^2 - x-^3 Right?
  41. A

    Convert a polynomial to hypergeometric function

    i want to write a hypergeometric function (2F1(a,b;c,x)) as function of n that generate polynomials below n=0 → 1 n=1 → y n=2 → 4(ω+1)y^2-1 n=3 → y(2(2ω+3)y^2-3) n=4 → 8(ω+2)(2ω+3)y^4-6(6+4ω)y^2+3 ... → ... 2F1(a,b;c,x)=1+(ab)/(c)x+(a(a+1)b(b+1))/(c(c+1))x^2/2!+... the...
  42. R

    Calculating P(2013) of Polynomial P(x) of Degree 2012

    P(x) is polynomial of degree 2012, P(k)=2^k, k=0,1,...,2012. Find P(2013)
  43. anemone

    MHB My TOP Favorite Polynomial Challenge

    Like I mentioned in the title, this is probably one of the greatest challenge problems (I've seen so far) that designed for, hmm, well, for a challenge!:o Let $x_1$ be the largest solution to the equation $\dfrac{6}{x-6}+ \dfrac{8}{x-8}+\dfrac{20}{x-20}+\dfrac{22}{x-22}=x^2-14x-4$ Find the...
  44. J

    Irreducible Polynomial of Degree 3

    Homework Statement If p(x) ∈F[x] is of degree 3, and p(x)=a0+a1∗x+a2∗x2+a3∗x3, show that p(x) is irreducible over F if there is no element r∈F such that a0+a1∗r+a2∗r2+a3∗r3 =0. Homework Equations The Attempt at a Solution Is this approach correct? If p(x) is reducible, then there...
  45. K

    Power series absolute convergence/ Taylor polynomial

    1. What if absolute convergence test gives the result of 'inconclusive' for a given power series? We need to use other tests to check convergence/divergence of the powerr series but the matter is even if comparison or integral test confirms the convergence of the power series, we don't know...
  46. Math Amateur

    MHB Ideals in Polynomial rings - Knapp - page 146

    I am reading Anthony W. Knapp's book, Basic Algebra. On page 146 in the section of Part IV (which is mainly on groups and group actions) which digresses onto rings and fields, we find the following text on the nature of ideals in the polynomial rings $$\mathbb{Q} [X] , \mathbb{R} [X] ...
  47. anemone

    MHB Does the Polynomial $P(x)=x^3+mx^2+nx+k$ Have Three Distinct Real Roots?

    A polynomial $P(x)=x^3+mx^2+nx+k$ is such that $n<0$ and $mn=9k$. Prove that the polynomial has three distinct real roots.
  48. anemone

    MHB Can You Crack the Polynomial Challenge VII? Prove 4 Distinct Real Solutions!

    Let $p,\,q,\,r,\,s,\,t$ be distinct real numbers. Prove that the equation $(x-p)(x-q)(x-r)(x-s)+(x-p)(x-q)(x-r)(x-t)+(x-p)(x-q)(x-s)(x-t)+(x-p)(x-r)(x-s)(x-t)+(x-q)(x-r)(x-s)(x-t)=0$ has 4 distinct real solutions.
  49. anemone

    MHB What is the value for $a+b$ in the Polynomial Challenge VI?

    If $a,\,b$ are the two largest real roots of the polynomial $f(x)=3x^3-17x+5\sqrt{6}$, and their sum can be expressed as $\dfrac{\sqrt{m}+\sqrt{n}}{k}$ for positive integers $m,\,n,\,k$, find the value for $a+b$.
  50. TheSodesa

    Polynomial long division -- How does it work?

    Let's say I wanted to do the following calculation: (x^2 + 2x + 1) / (x+1) I've scrolled through some online guides, and they all show how to do it, but not the principle behind it. I'm specifically having trouble with the fact, that instead of dividing the largest degree term with the entire...
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