Polynomial Definition and 1000 Threads

  1. P

    Polynomial with at most n-1 solutions.

    Hi, Homework Statement I am expected to show that the polynomial a1xb1 + a2xb2 + ... + anxbn = 0 has at most n-1 solutions in (0,infinity), where a1,a2,...,an are real numbers different than zero, and b1,b2,...,bn are real numbers so that bj is different than bk for j different than k...
  2. P

    Finite Difference (Interpolating Polynomial)

    Homework Statement http://puu.sh/1QFsA Homework Equations The Attempt at a Solution I'm actually not sure how to do this question. How do i find Δx^2. I kind of understand the question but I don't know how to prove it. I know that Δy becomes dy when the width becomes...
  3. J

    Finding roots to a recursively defined polynomial of degree n

    Hello all, I have a series of polynomials P(n), given by the recursive formula P(n)=xP(n-1)-P(n-2) with initial values P(0)=1 and P(1)=x. P(2)=xx-1=x2-1 P(3)=x(x2-1)-(x)=x3-2x ... I am confident that all of the roots of P(n) lie on the real line. So for P(n), I hope to find these roots. I...
  4. dkotschessaa

    Linear Algebra - Find a Polynomial

    Homework Statement Find all polynomials of the form a + bx + cx^2 that: Goes through the points (1,1) and (3,3) and such that f'(2) = 1Homework Equations a + bx + cx^2 f'(x) = x+2cx f'(2) = 2 + 4c polynomial through (1,1) = a + b1 + c1 = 1 polynomial through (3,3) = a + b3+ c3^2 = 3 The...
  5. P

    Roots of derivative of polynomial.

    Hi, Homework Statement I am asked to prove that given all roots of a polynomial P of order n>=2 are real, then all the roots of its derivative P' are necessarily real too. I am permitted to assume that a polynomial of order n cannot have more than n real roots. Homework Equations...
  6. B

    Taylor Polynomial. Understanding.

    Homework Statement Last exam in my school this exircise was given: From norweagen: " Decide the Taylor polynomial of second degree of x=0 of the function: f(x) = 3x^3 + 2x^2 + x + 1 I found the Taylor polynomial of second degree to be: 2X^2+X+1, which is correct. If I get an...
  7. A

    Puzzled about characteristic polynomial output from my calc

    Hello everyone, first time poster, long time reader here! I'm an ex-math major and while I'm no longer pursuing a degree anymore in mathematics, I still continue onwards in my spare time trying to learn as much as I can about it because it's always been something I've enjoyed partaking in and...
  8. H

    Is There a Positive Constant for a Polynomial Inequality with Two Variables?

    Hi Let p(x,y)≥0 be a polynomial of degree n such that p(x,y)=0 only for x=y=0.Does there exist a positive constant C such that the inequality p(x,y)≥C (IxI+IyI)^n (strong inequality!) holds for all -1≤x,y≤1? The simbol I I stands for absolute value.
  9. L

    Polynomial finite fields; ElGamal decryption

    Homework Statement Given some ElGamal private key, and an encrypted message, decrypt it. Homework Equations Public key (F_q, g, b) Private key a such that b=g^a Message m encrypted so that r=g^k, t=mb^k Decrypt: tr^-a = m The Attempt at a Solution My problem is finding r^-a...
  10. Square1

    Irreducibility of Polynomial part deux

    Ok I promise this time it is not a homework type question. If someone could direct with a name of a theorem here, then I'll go ahead and google it, otherwise have a look. I have a chunk of notes that I'm confused about. We're not shown any proofs here or any explanations, just what is seen. It...
  11. D

    Is this cublc polynomial function solvable?

    Here is a very difficult cubic polynomial. x^3 - x - 2 = 0 I am wondering whether it is solvable or not. Please think about it.
  12. R

    Given min. polynomial of a, find min. polynomial of 1/a

    Homework Statement Given that the minimal polynomial of a over rationals is x^4+x+8, find the minimal polynomial for 1/a over Q. Homework Equations I know there is a lot of work done out there for finding the min. polynomials of a^k for k>0, however I've never seen anything with a^k for...
  13. R

    Taylor Polynomial of Smallest Degree to approximation

    Hey, guys. Having problems with this question because I don't exactly know how to begin it. Homework Statement The problem states to: "Find the Taylor polynomial of smallest degree of an appropriate function about a suitable point to approximate the given number to within the indicated...
  14. C

    What is the Quadratic Maclaurin Polynomial for f(x)=x*sin(x)?

    Homework Statement I'm having a bit of trouble with this Maclaurin Series question. It should be simple enough but I can't get the answer which is given as x2. It's been a while since I've done series and my being rusty is a little annoying. Hopefully someone can help :) Consider...
  15. A

    MHB Polynomial and Rational Functions

    For the years 1998-2009, the number of applicants to US medical schools can be closely approximated by: A(t)= -6.7615t4+114.87t3-240.1t3-2129t2+40,966 where t is the number of years since 1998. a) graph the number of applicants on 0<= t <= 11 b) based on the graph in part a, during what...
  16. Square1

    What role do prime numbers play in proving the irreducibility of polynomials?

    Hi. There is a polynomial f = (x^3) + 2(x^2) + 1, f belongs to Q[x]. It will be shown that the polynomial is irreducible by contradiction. If it is reducible, (degree here is three) it must have a root in Q, of the form r/s where (r,s) = 1. Plugging in r/s for variable x will resolve to r^3 +...
  17. Square1

    Why Do Prime Numbers Play a Role in Proving the Irreducibility of Polynomials?

    Hi. There is a polynomial f = (x^3) + 2(x^2) + 1, f belongs to Q[x]. It will be shown that the polynomial is irreducible by contradiction. If it is reducible, (degree here is three) it must have a root in Q, of the form r/s where (r,s) = 1. Plugging in r/s for variable x will resolve to r^3 +...
  18. L

    How to factor 3rd degree polynomial with 3 terms

    -x^3+12x+16 Every single technique I read about online of how to factor 3rd degree polynomials, it says to group them. I don't think grouping works with this. I tried but it didn't work, since there's only 3 terms. Apparently I'm not supposed to have a cubic variable without a squared...
  19. camilus

    Product and intersection of ideals of polynomial ring

    Let k[x,y,z,t] be the polynomial ring in four variables and let I=<x,y>, J=<z, x-t> be ideals of the ring. I want to show that IJ=I \cap J and one direction is trivial. But proving I \cap J \subset IJ has stumped me so far. Anyone have any ideas?
  20. J

    Discriminant of Characteristic Polynomial > 0

    Homework Statement Show that the descriminant of the characteristic polynomial of K is greater than 0. K=\begin{pmatrix}-k_{01}-k_{21} & k_{12}\\ k_{21} & -k_{12} \end{pmatrix} And k_i > 0 Homework Equations b^2-4ac>0 The Attempt at a Solution I have tried the following...
  21. F

    What is the existence and value of the infimum of a polynomial function?

    Homework Statement Given the function "P" defined by: P(x) := [SIZE="3"]x^2n + [SIZE="3"]a2n-1*[SIZE="3"]x^2n-1 + ... + [SIZE="3"]a1[SIZE="3"]x + [SIZE="3"]a0; prove that there exists an [SIZE="3"]x* in |R such that P(x*) = inf{P(x) : x belongs to | R} Also, prove that: |P(x*)| =...
  22. P

    Aproximating a morse potential using a taylor polynomial

    I am not going to post my question because I want to find out how to actually use the taylor polynomial and morse potential and then apply that to my problem. Say I have to approximate the morse potential using a taylor series expanding about some value. This will then find me the force...
  23. G

    Calculating the Minimal Polynomial for a Given Matrix A

    I've been given a matrix A and calculated the characteristic polynomial. Which is (1-λ)5. Given this how does one calculate the minimal polynomial? Also just to check, is it correct that the minimal polynomial is the monic polynomial with lowest degree that satisfies M(A)=0 and that all the...
  24. V

    Roots of a third degree polynomial

    Homework Statement Knowing that the equation: X^n-px^2=q^m has three positive real roots a, b and c. Then what is log_q[abc(a^2+b^2+c^2)^{a+b+c}] equal to? Homework Equations a + b + c = -(coefficient \ of \ second \ highest \ degree \ term) = -k_2 abc = -(constant \ coefficient) =...
  25. D

    MHB What are the roots of this polynomial with a beta coefficient?

    $\beta m^5 + m^2 + 1 =0$ How do I find the roots?
  26. E

    Find the cubic polynomial satisfying f(0) = -5, f(1) = 0, f(2) = 15, f(3) = 52.?

    Here is the correct answer: 2x^3 - x^2 + 4x - 5 My attempt only gives me one cubed term and the other terms are also marginally off, any help on who can show me how to get the correct answer will be hugely appreciated
  27. K

    Legendre Polynomial and Rodrigues' Formula

    I am reading Jackson's electrodynamics book. When I went through the Legendre polynomial, I have a question. In the book, it stated that from the Rodrigues' formula we have Consider only the odd terms...
  28. V

    Roots of a fourth degree polynomial

    Homework Statement z^4 - z^2 + 1 = 0 is an equation in ℂ. Which of the following alternatives is the sum of two roots of this equation: (i) 2√3; (ii) -(√3)/2; (iii) (√3)/2; (iv) -i; (v) i/2 Homework EquationsThe Attempt at a Solution All I know is that the sum of all roots should equal 0...
  29. U

    Condition for this polynomial to be a perfect square

    Homework Statement The condition that x^4+ax^3+bx^2+cx+d is a perfect square, is Homework Equations The Attempt at a Solution If the above polynomial will be a perfect square then it can be represented as (x-\alpha)^2(x-\beta)^2 where α and β are the roots of it.This means that two...
  30. A

    Bernstein's Polynomials for f(x)=x and f(x)=x^2: Sequence and Formula

    Find the sequence (B_nf) of Bernstein's polynomials in a) f(x)=x and b) f(x)=x^2 Answers (from my textbook): a) B_nf(x) = x for all n. b) B_nf(x) = x^2 + \frac{1}{n} x (1-x) I know that the bernstein's polynomial is: B_nf(x) = \sum_{k=0}^n f (\frac{k}{n}) \binom{n}{k} x^k...
  31. 5

    Third degree Taylor polynomial in two variables

    Homework Statement Find the third degree Taylor polynomial about the origin of f(x,y) = \frac{\cos(x)}{1+xy} Homework Equations The Attempt at a Solution From my ventures on the Internet, this is my attempt: I see that \cos(x) = 1 - \frac{1}{2}x^2 + \frac{1}{4!}x^4 - \cdots...
  32. M

    Finding Roots of Bivariate Polynomial Surfaces: A Slice Technique Approach

    Is there a formula for finding the roots of a bivariate polynomial in x and y with the form: (a^2)xy+abx+acy+bc Where a, b, and c are constants, of course.
  33. J

    Finding roots of the derivative of a polynomial.

    hey i'm trying to figure out how to approach part b of this problem, http://imageshack.us/a/img850/6059/asdasdno.jpg so i can see that you can apply the mean value theorem to p'(x) so there exists some c between a and b such that f'(c) = [f(b) - f(a)] / (b-a)=0 so p'(x)...
  34. vrmuth

    Is there formula for zeres of a cubic polynomial

    is there any general formula to find out zeros of a cubic polynomial that will give you all the zeros ? if not please tell me what are the different methods to find out the zeros , guessing and trial and error , numerical etc. i want to see where are each methods useful and is there...
  35. C

    MHB Louis's Question from YahooAnswers:Fp1 Polynomial and roots question Help?

    Question: 1.Find the range of values of \(a\) for which \[(2-3a)x^2+(4-a)x+2=0\]has real roots.2. If the roots of the equation \(4x^3+7x^2-5x-1=0\) are \(\alpha\) , \(\beta\) and \( \gamma\),find the equation whose roots are: (a) \( \alpha+1,\beta+1\) and \(\gamma+1\) (b) \(\alpha^2 \beta^2\)...
  36. Z

    Find a polynomial p(t) of degree 6 which

    Find a polynomial p(t) of degree 6 which has a zero of multiplicity 2 at t = 1 and a zero of multiplicity 3 at t = 2, and also satisfying: p(0) = 2 and p`(0) = 1. What is the other root of p(t)? Attempt at solution: zero of multiplicity 2 at t =1 implies (t-1)^2 is a factor or p(1) = 0...
  37. C

    Determining the second order polynomial from the intersection points

    Homework Statement Let's say that we have a second order polynomial function, and we know all of the points where it intersects with the x and y axis. Ex: (-2; 0), (0; 2), (1; 0) How does on determine the ax^2+bx+c polynomial form based on that? Homework Equations - The Attempt at...
  38. H

    Writing out the span of this polynomial vector space?

    Homework Statement The problems states "All polynomials of the form p(t)= at^2, where a is in R." I'm supposed to see if it is a subspace of Pn. I've already done that but the book's answer is that it spans Pn by Theorem 1, because the set is span{t^2} Homework Equations Theorem states "1 If...
  39. U

    Solving a Polynomial with Real Coefficients and Real Zeroes

    Homework Statement Let f(x) = x^{4}+ax^{3}+bx^{2}+cx+d be a polynomial with real coefficients and real zeroes. If |f(i)| = 1, (where i = \sqrt{-1}) then find a+b+c+d. Homework Equations The Attempt at a Solution f(i) = 1-b+d+ci-ai Taking modulus |f(i)|= |1-b+d+i(c-a)|...
  40. A

    How do you find the minimal polynomial?

    Homework Statement If we have a transformation matrix \begin{bmatrix} 1 & 2 & 4 \\0 & 0 & 0 \\0 & 0 & 0 \end{bmatrix} Homework Equations The Attempt at a Solution I found the characteristic polynomial of this matrix: x^3 - x^2 = x^2(x-1) ...can anybody please help me...
  41. N

    Finding polynomial function with given zeros

    Homework Statement find the polynomial function p(x) with zeros, -1, 1, 3 and P(0)=9 Homework Equations all i have is (x^2-1) and (x-3) The Attempt at a Solution
  42. N

    Is 2 a Root of the Polynomial 4x^3 - 3x^2 - kx - 4k^2 = 0?

    Homework Statement if 2 is a root of 4x^3-3x^2-kx-4k^2= 0 find th value of k Homework Equations The Attempt at a Solution
  43. J

    Showing a polynomial has at least one zero outside the unit circle.

    The first thing that we should notice is that the leading coefficient $a_n = 1$. I was thinking about considering the factored form of p. I googled, and there is an algorithm called the "Schur-Cohn Algorithm" that is suppose to answer exactly this, but I can't find any information on it or...
  44. 1

    Polynomial Span related problem Linear Algebra

    Homework Statement Consider the vector space F(R) = {f | f : R → R}, with the standard operations. Recall that the zero of F(R) is the function that has the value 0 for all x ∈ R: Let U = {f ∈ F(R) | f(1) = f(−1)} be the subspace of functions which have the same value at x = −1 and x = 1...
  45. 1

    Polynomial Span and Subspace - Linear Algebra

    Homework Statement Consider the vector space F(R) = {f | f : R → R}, with the standard operations. Recall that the zero of F(R) is the function that has the value 0 for all x ∈ R: Let U = {f ∈ F(R) | f(1) = f(−1)} be the subspace of functions which have the same value at x = −1 and x = 1...
  46. M

    Taking the derivative of a polynomial fraction?

    Taking the derivative of a polynomial fraction?? b]1. Homework Statement [/b] Ok, so the question wants me to differentiate f(x)= (x)/(x+1). We are supposed to use the definition of the derivative f'(x)= (limit as h->0) [f(x+h)-f(x)]/(h). We also have learned the power rule. I did the formula...
  47. T

    Quick check of 4 term polynomial factorised

    Could someone quickly go over my working, as I am not 100% sure I have done it the right way. I will show and explain my working step by step. $$ at^2-4a + 2t^2-8$$ I first grouped the values: (at^2-4a) + (2t^2-8) I then factorised these equations into: a(t^2-4a) + 2(t^2-4) I...
  48. B

    MHB Proving an entire function is a polynomial under certain conditions

    Hello, This was an exam question which I wasn't sure how to solve: Suppose f is entire and |f(z)| \leq C(1+ |z|)^n for all z \in \mathbb{C} and for some n \in \mathbb{N}. Prove that f is a polynomial of degree less than or equal to n. I know that f can be expressed as a power series, but I'm...
  49. tom.stoer

    Solution of polynomial equations

    Suppose there is a set of complex variables \{x_i,\,i=1 \ldots M;\;\;y_k,\,k=1 \ldots N\} and a polynomial equation p(x_i, y_k) = 0 Is there a way to prove or disprove for such an equation whether it can be reformulated as f(x_i) = g(y_k) with two functions f and g with...
  50. ElijahRockers

    Determining Polynomial Subspaces in P4

    Homework Statement Determine whether the following are subspaces of P4: a) The set of polynomials in P4 of even degree b) The set of all polynomials of degree 3 c) The set of all polynomials p(x) in P4 such that p(0) = 0 d) The set of all polynomials in P4 having at least one real root The...
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