Polynomial Definition and 1000 Threads

  1. E

    Factoring a third degree polynomial as part of a limits problem

    Homework Statement I have a limit problem, however I do know how to work limits, I guess what I need is more of a refresher on how to work third degree polynomials. The polynomial(s) I am trying to work with are the following: x3-2x2+2x-15 -and- x3-5x2+10x-12 The limit is a limit where x...
  2. R

    A Why Question:Taylor Polynomial of e^x over x?

    So I was just wondering why when you approximate using the Taylor Polynomials for something like e^x/x at x = 0 you can just find the approximation for e^x and make it all over x, could you do the same for like e^x/x^2 or e^x/x^3? I hope my question makes sense... thanks
  3. R

    Chebyshev polynomial - induction problem

    Homework Statement Let Tn(x)=cos(narccosx) where x is real and belongs to [-1,1] and n E Z+ Find T1(x). Show that T2(x)=2x^2 - 1. Show that Tn+1 (x) + Tn-1 (x) = 2xTn(x) Hence, prove by induction that Tn(x) is a polynomial of degree n. The Attempt at a Solution Since cosθ=x and arccosx=θ we...
  4. M

    Find the MacLaurin polynomial of degree 5 for F(x).

    Homework Statement Homework Equations The Attempt at a Solution I keep getting the answer 1- 96/4!*x^4. Can't find where I'm going wrong.
  5. A

    Quaternion Polynomial Equation

    I'm working on the following: "Prove that x^2 - 1=0" has infinitely many solutions in the division ring Q of quaternions." The Quaternions are presented in my book in the representation as two-by-two square matrices over ℂ. The book gives that for a quaternion (sorry for the terrible...
  6. J

    Linear Algebra - Linear Transformation of a polynomial

    Homework Statement Let h: \mathbb{P_2} \rightarrow \mathbb{P_2} represent the transformation h(p(x)) = xp'(x) + p(1-x) for every polynomial p(x) \in \mathbb{P_2}. Find the matrix of h with respect to the standard basis \{1, x, x^2\} Homework Equations Matrix A of transformation: {\bf A}...
  7. M

    Appropriateness of Constrained Segmented Univariate Polynomial Regression Model

    Hi all, I've learned that in unconstrained polynomial regression, the optimal order can be determined using two F tests : one to test for the significance of the overall regression, the other to test for the significance of the higher coefficients (assuming the first test passed of course)...
  8. J

    Mathematica [Mathematica] Sorting polynomial terms

    Hi. Can someone explain to me how to sort a Series so that the terms are in increasing powers of the exponent? For example the code: myseries = Normal[ Series[Sqrt[1 - w], {w, 0, 5}]] /. w -> 1/z produces 1-\frac{7}{256 z^5}-\frac{5}{128 z^4}-\frac{1}{16 z^3}-\frac{1}{8 z^2}-\frac{1}{2...
  9. A

    Minimal Polynomial and Jordan Form

    Homework Statement Suppose that A is a 6x6 matrix with real values and has a min. poly of p(s) = s^3. a) Find the Characteristic polynomial of A b) What are the possibilities for the Jordan form of A? c) What are the possibilities of the rank of A? Homework Equations See below...
  10. L

    Factoring polynomial over rings

    Homework Statement Factor x^3+3x+6 over Z5, Z10, Z, Q and ℝ. 2. The attempt at a solution For Z5, I have the roots of x^3+3x+1 in Z5, x=2=-3 and x=3=-4, so x+3 and x+4 are factors. By long division of x^3+3x+1, it is found that x+3 is a repeated factor, so x^3+3x+6=(x+4)(x+3)^2. For Z and...
  11. G

    What Is the Correct Solution to the Differential Equation xy'^2 + yy' = 0?

    xy'^2 + yy' = 0 where y' = dy/dx The answer is C1 = y and C2 = xy but I get this: y'(xy' + y) = 0 where y' = 0 and thus y = C1 For the other solution: xy' + y = 0 y' = -y/x y = -y ln x + C2 C2 = y + y ln x Full question is here: http://www.cramster.com/solution/solution/640396
  12. R

    Polynomial transformation of random variable

    Homework Statement Given a random variable X with a known distribution (e.g. a beta distribution), find the distribution of f(X) = X^2 + X The Attempt at a Solution I've tried the normal approaches: the standard transformation theorem; conditioning on X; Laplace transformation, etc...
  13. D

    Proving Polynomial Irreducibility over Z

    Homework Statement Prove that the polynomial $(x-1)(x-2)...(x-n) + 1$ is irreducible over Z for n\geq 1 and n \neq 4Homework Equations N/AThe Attempt at a Solution Let $f(x) = (x-1)(x-2) \cdots (x-n) + 1$ and suppose $f(x) = h(x)g(x)$ for some $h,g \in \mathbb{Z}[x]$ where $\deg(h), \deg(g) <...
  14. A

    Does this polynomial produce only prime numbers?

    I'm trying to find a general formula for an algebraic equation, I'm studying the behavior of ∏_{i=2}^n(1-\frac{1}{i^m}) for m=3 and so far I've seen that I can find a general formula if n^2 + n + 1 produces only prime numbers. if not, it would get way harder to find a general formula for it by...
  15. D

    Differentiation of a polynomial function

    Hi guys I'm getting into a little trouble when differentiating polynomial functions. How do you differentiate f(x)=ax+b/cx+d ? Is there other ways of calculating this apart from the chain rule ? Thanks for any help.
  16. Peeter

    How to arrive at Bessel function solution to 1D polynomial potential

    My quantum text, leading up to the connection formulas for WKB and the Bohr-Sommerfeld quantization condition states that for \begin{align}u'' + c x^n u = 0 \end{align} one finds that one solution is \begin{align}u &= A \sqrt{\eta k} J_{\pm m}(\eta) \\ m &= \frac{1}{{n + 2}} \\ k^2 &=...
  17. Shackleford

    Analysis: Taylor Polynomial Approximation

    For #4, I'm mostly confident I did it correctly. In determining the error, we're supposed to find the maximum absolute value on an interval I. I set I = (0,2pi). Is that right? http://i111.photobucket.com/albums/n149/camarolt4z28/4-1.png For #5...
  18. G

    Polynomial Subspace Dimension & Basis Calculation

    Homework Statement Let M be a subspace of the vector space \mathbb{R}_2[t] generated by p_1(T)=t^2+t+1 and p_2(T)=1-t^2, and N be a subspace generated by q_1(T)=t^2+2t+3 and q_2(T)=t^2-t+1. Show the dimension of the following subspaces: M+N, M \cap N, and give a basis for each...
  19. M

    Continuity of Polynomial Functions in their Domain

    The first hypothesis is that f is continuous on [a,b]... Is there a more concise mathematical way of saying... "because the function f is a polynomial it is continuous in its domain."? Because I rather not write that on my test it looks sloppy and non professional...
  20. L

    Did I Divide This Polynomial Correctly?

    As part of solving a DE I need to make this friendlier to integrate: \frac{2u}{1+u^{-2}} I figured trying to divide it couldn't hurt. I got: u^{-1}+u^{-3} I can't type out all the steps easily, I'm on a mobile device at the moment. That answer looks suspect, did I do it correctly?
  21. S

    Hermite Polynomial Reccurence Relation

    Homework Statement Prove, using Rodrigues form, that Hn+1=2xHn -2nHn-1 Homework Equations The Rodrigues form for Hermite polynomials is the following: Hn = (-1)nex2\frac{d^n}{dx^n}(e-x2)The Attempt at a Solution Hn+1 = (-1)n+1ex2\frac{d^(n+1)}{dx^(n+1)}(e-x2) where...
  22. M

    Solving Polynomial Functions: Find x in 0<|x|≤1/2

    Homework Statement f:ℝ→ℝ x:→sqrt(x^2+1)-lxl Homework Equations calculate f^-1(]0,1]) The Attempt at a Solution well i chose a y from ]0,1] and tried to find an x that solves the problem like the following. 0<sqrt(x^2+1)-lxl≤1 at the end i got the following...
  23. K

    Finding quadratic maclaurin polynomial

    Homework Statement the question asks to find the quadratic maclaurin polynomial for f(x) Given f(x) = x sin(x)The Attempt at a Solution i know that a maclaurin series is when a=0 in a taylor series. i did the 1st-5th derivatives of f(x) and then used the formula for taylor polynomial and set...
  24. K

    Using Intermediate Value Theorem to prove # of polynomial roots

    I've heard there's a proof out there of this, basically that (I think) you can use the intermediate value theorem to prove that an Nth-degree polynomial has no more than N roots. I'm not in school anymore, just an interested engineer. Does anyone know where I can find this proof or any...
  25. S

    Eigenvalues,charateristic polynomial

    Homework Statement http://img213.imageshack.us/img213/7867/problemeigen.png Uploaded with ImageShack.us Homework Equations http://img339.imageshack.us/img339/771/equationh.jpg Uploaded with ImageShack.usThe Attempt at a Solution so i tried doing the problem i going to use L for lambda i...
  26. M

    How Do You Prove the Range of a Square Root Polynomial Function?

    Homework Statement f:[1,+∞[→ℝ x→sqrt(x+2)-sqrt(x-1)Homework Equations show that f([1,+∞[)=]0,sqrt(3)]The Attempt at a Solution Any tips on how to start it.
  27. M

    Is the Function f(x) = 2x/(x-1) Both Injective and Surjective?

    Homework Statement f:]1,+∞[→]2,+∞[ x→ 2x/(x-1) Homework Equations Prove that f is injective and serjective. The Attempt at a Solution I already proved that it's injective by stating the injectivity law: for every (a,b)ε]1,+∞[: f(a)=f(b) implies a=b so: 2a/(a-1)=2b/(b-1)...
  28. S

    Expressing a root of a cubic polynomial as a series

    Is there a good way to do this? I have an equation, say x^3 - 4*x^2 + 2, so a=1, b=-4, c=0, d=2. Is there an easy way to express the largest root of such an equation? In this case, the roots are: 3.8661982625090223 -0.65544238154983 0.7892441190408067 But I am trying to find an...
  29. J

    Taylor Polynomial with Remainder Question

    Homework Statement What is the minimal degree Taylor polynomial about x=0 that you need to calculate sin(1) to 3 decimal places? 6 decimal places? Homework Equations R_nx = f^(n+1)(c)(x-a)^(n+1)/(n+1)(factorial) The Attempt at a Solution I have attached my attempt. I am stuck on the...
  30. U

    Interpreting results of a polynomial fit

    I am currently working on a gamma ray spectroscopy lab in which i have just fit a polynomial to my calibration points. The calibration points are in a relatively straight line, from x=40 to x=450, and y=34 to y=1300 for the first and last end points respectively. Where X is channel number, and Y...
  31. S

    MATLAB How to Generate Symbolic Polynomial in MATLAB with Given Parameters?

    I am trying to get MATLAB to be able to produce a symbolic polynomial and am having some issues. The polynomial I would like it to produce is given a d and k, X(k+1)-X(k-d)-X(k-d-1)-...-1 What I have so far is k = 5; d = 3; syms X; i = 0; while (k-(d+i) >= 0) terms(i+1) =...
  32. K

    What is the simplest way of selecting the last N terms of a polynomial?

    If you have a polynomial like (1+x)^6 = x^6+6 x^5+15 x^4+20 x^3+15 x^2+6 x+1, What function would you use to pick only the last N terms? For instance, for N=3 pick x^6+6 x^5+15 x^4 I've being using sum of a binomial times something, but was wondering if there is anything more simple. Thanks!
  33. B

    Ode 2nd degree with a polynomial as a coefficient

    Hi friends, I have been trying to solve the ode of second degree below with respect to z: d2y/dz2=(i/a*z+b)*y i is the complex i, a and b are constants i ended up with the summation of bessel functions of first end second kind. Then I checked with MATLAB ode solver it gives no...
  34. D

    Is xp(x) in the Range of T for Given Polynomials?

    Homework Statement Let T: P2-P3 be the linear transformation defined by T(p(x)) = xp(x). Which of the following are in R(T)? (a) x2 (b) 0 (c) 1 + x Homework Equations R(T) is the the set of all vectors in P3 which are images under T of vectors in P2. The Attempt at a Solution...
  35. N

    Finding all zeros of a Polynomial

    Homework Statement Find all zeros of k(x) = 4x^4-7x^2+3x Homework Equations n/a The Attempt at a Solution I don't know if I should find the factors of 0 and 4.. Can you help me what to start out with.. I can do other ones like p(x) = 3x^3-37x^2+84x-24. But this problem k(x) =...
  36. D

    Need help plotting a 4th order polynomial

    I need help from someone with a graphing calculator. My little brother lost my graphing calculator and synthetic division I can't make work becasue the terms aren't exactly friendly. The equation is, 24.059025x^4 + 94.98287069x^3 + 44.56696001x^2 - 827.1103204x = -1067.832496 The more...
  37. S

    Chebshev polynomial approximation

    Homework Statement Hi every body I am triyng to find a polynolial approximation to the function: f(x)= (x+2)ln(x+2) using the chebyshev polynomials, the idea is to use MATLAB to find the coeefficients of the approximation poly. using the comand double(int(...)) but this command...
  38. X

    Lagrange Polynomial Interpolation

    Homework Statement Find the polynomial p(x) of degree 20 satisfying: p(-10) =p(-9) = p(-8) = ...=p(-1) = 0 p(0) = 1 p(1) = p(2) = p(3) = ...p(10) = 0 Homework Equations L(x) := \sum_{j=0}^{k} y_j \ell_j(x) The Attempt at a Solution i tried using the formula above: a =...
  39. DryRun

    Find all complex roots of polynomial

    Homework Statement Given 2 + 3i is one root of the equation: x^4 - 6x^3 + 26x^2 -46x +65 = 0 Find the remaining roots. The attempt at a solution I am thinking about this as a possible solution although it is too long to be plausible, unless I'm wrong. let x = a + bi and then replace in the...
  40. J

    Characteristic polynomial coefficients

    For any characteristic polynomial determined from A - eI (where A is a nxn matrix, e is an eigenvalue and I is the identity matrix), is it a rule that the coefficient associated with the char. polynomail term of highest degree must be positive ? My tutor made a theory that if the...
  41. A

    Polynomial Functions (word problem)

    Homework Statement A quartic function has x-intercepts of -5, -1, 2, and 4. The point (3.-8) lies on the curve. Determine an equation of the function. Homework Equations The Attempt at a Solution y = k (x+5)(x+1)(x-2)(x-4) Expanded form: f(x)=kx^4 + 9x^2 - 38x + 40 <---My...
  42. W

    Solving Polynomial Inequalities Using Synthetic Division and the PQ Rule

    Homework Statement 4x5-16x4+9x3+23x2-15x-9 > 0 Homework Equations Synthetic division PQ Rule? The Attempt at a Solution Don't know how or where to begin
  43. N

    Word problem polynomial f(x) help

    Homework Statement 2 People build a sandcastle of 36cm by 48cm by 60cm. Later they learn that the box will be smaller; a certain amount will be taken off each of the length width and height Homework Equations The Attempt at a Solution a) write a p(x) > (36-x) (48-x) (60-x)...
  44. E

    Taylor Polynomial Approximations.

    Hello, I'm new here, nice to meet you guys i was in class today and just didn't understand the taylor polynomial approximation, the professor started out approximating a function by polynomials of degree N, he first showed us how a linear polynomial was a crude approximation of the function...
  45. N

    Polynomial f(x) word problem help

    Homework Statement Kaylas lemonade stand has experienced rises /falls in sales caused by temperature changes over 2 summers. Her sales over the first two weeks of summer were tracked according to the model S(x) = x^3 -12x^2 +36x, where x is the number of days and S(x) is the number of sales...
  46. J

    Using Taylor Polynomial for Laplace Transforms

    Ive attached the problem and my work in the pic. Questions: Am I even applying the taylor polynomial the correct way? (I never learned taylor series, but I was supposed to be taught in the pre-requisite class) Am I suppose to plug in c=4? I am not so sure about how the U4(t) works...
  47. N

    Understanding Polynomial Functions: Analyzing h(x) = 3x + 2x

    Homework Statement Why is this not a polynomial function? h(x) = 3x + 2x Homework Equations The Attempt at a Solution 3x+2x = 5x. 5x is a linear function with a degree of 1, why is this not a polynomial funct?
  48. N

    Quick question of polynomial function

    Homework Statement Determien an euation for each polynomial function described below state whether the function is even, odd or neither. Sketch a graph of each. Homework Equations The Attempt at a Solution My question is.. If youre given information like this :: a) A quintic...
  49. N

    Polynomial function transformation help

    Homework Statement What is the difference between f(x)= x^3 , and g(x) = x^3 - x What does that -x do to the function and how do you represent it graphically? What about f(x) = 3x^3 +x Homework Equations The Attempt at a Solution No idea, wolframalphad the graph but i...
  50. N

    Determining if polynomial function

    Homework Statement We know that a polynomial function is anything with a positive exponent and a rational number. a) - / x^3 -4 d) 3x^-1 - 11 g) y= [sqrt of term]3x^2 -5x Homework Equations The Attempt at a Solution c) 1 / x^3 - 4 (do we use exponents to verify ?)...
Back
Top