Roots Definition and 962 Threads

  1. B

    What Are the Sum and Product of the Roots of This Complex Polynomial?

    Question that I came across and that has stumped me for about a week hehe. Let p(z)=z^n +i z^{n-1} - 10 if \omega_j are the roots for j=1,2,...,ncompute: \sum_{j=1}^n \omega_j} and \prod_{j=1}^n \omega_j}
  2. T

    Limit of function with square roots

    for sqr root of (n + sqr root (n) ) - sqr root (n),is the answer = zero or infinity so converges or diverges??
  3. M

    What are the solutions to the equation (z+1)^4=1-i?

    find all solutions of the given equation: (z+1)^4=1-i im not sure if i did this right, but here's what i did the first thing that i did was notice that 1-i = 2^1/2 * (cos (pi/4) + i*sin(pi/4)) then i found z= [2^(1/2*1/4) * (cos (pi/4) + i*sin (pi/4) )^1/4] -1 then using de moivre's thrm...
  4. EnumaElish

    Medical Biological roots of passive agressive (PA) personality? PA disorder?

    Does anyone have insights or a perspective on the possible biological roots of PA behavior (or disorder)? I am not a psychologist, psychiatrist, or biologist, but when I think of the evolution of the species it kind of seems obvious that the mammals lived a hard life under the dinosaurs' feet...
  5. L

    Non integer square roots and pi = irrational?

    Since one can construct the length of a non-integer square root by drawing accurate triangles, and can draw a circle with a circumference of pi, then shouldn't one be able to plot corresponding non-integer square roots and pi on a number line? I know these numbers are supposedly irrational, but...
  6. D

    Counting Primitive Roots in Finite Fields without Group Theory

    I have the definition that if F is a finite field then a \in F is a primitive root if ord(a) = |F|-1. Now what I don't understand is how exactly are there \phi(|F|-1) primitive roots? (Note: This material is supposed not to use any group theory.)
  7. A

    Proving Equal Roots in ar^2+br+c=0 with L[e^(rt)]

    If ar^2+br+c=0 has equal roots r1, show that L[e^(rt)]=a(e^(rt))``+b(e^(rt))`+ ce^(rt)=a{(r-r1)^2}e^(rt) could someone offer some advice?
  8. E

    A conjecture about the roots of real functions

    All the roots of a real function f(x) are real unless. 1.K(x) is a Polynomial of degree k 2.f(x)=exp(g(x)) where g(x) is different from ln of something 3.f(z) with z=u+iv is invariant under the transformation of v=-v with f(u+iv)=F(u-iv).. 4.the function f includes some of the functions...
  9. D

    How were logs and roots calculated before calculators?

    I'm not sure whether this is the correct forum, so I apologise if it's in the incorrect forum. Anyway, when studying A level maths a few years ago, we came across a technique for calculating roots that my teacher claimed was used before calculators were invented. I can't remember the actual...
  10. A

    Finding a Basis for O.D.Es with Same Roots

    why is it that when you have the same roots to an O.D.E., you usually add an x or x^2 to get a basis?
  11. J

    Solving Fractions with Roots: an Example

    Hey having a bit of trouble with this question, not sure what to do! QUESTION - express the fraction in the form a + b rootc / d 3 + root24 / 2 + root6 ------------------------------------------ (3 + root24 / 2 + root 6) x (2 - root 6 / 2 - root 6) Simplifying gives (6 -...
  12. 8

    Finding Roots of b1 and b2 Between 0 and 30

    Ok, i got two funktions: b1:=(x/10)+sin((x/3)+(Pi/2)); and b2:=(1-2*cos((x/4)+(Pi/2))); I need to determine all the roots between 0 < x > 30 If I plot the functions i see that there should be two roots plot([b1,b2],x=0..30); But when try to get maple to calculate the roots It only...
  13. U

    Discovering Cubic Root Solutions for Scientists

    hello how can i finding roots to cubics?? explain by example :smile:
  14. E

    Are all the roots of an infinite polynomial real?

    let be the function f(x) so we have that if x is a root also x* is a root, but we have that x is NEVER a pure imaginari number,i mean x is always different from x=ia the my question is if this means that all the roots will be real,the only counterexample i find is...
  15. U

    Real find both roots of the equation

    x^2 +6x +k=0 has one root (a) where I am (a) =2, If k is real find both roots of the equation and k So i got b+ 2i is the root (b+2i)^2 +6(x+2i) +k=0 and after expanding it out, i have no clue what to do. Please help. THanks
  16. P

    Find Primitive Root Modulo 125 - The Easier Way

    How would I go about finding a number that is a primitive root modulo 125? There definitely exists a primitive root since 5^3 =125 The problem basically comes down to finding 'a' (primitive root); a^50 congruent to -1 (mod 125) Anyone know a way apart from trial and error? Thanks
  17. M

    Help with finding roots for transfer functions

    I am in a Systems and Vibrations class but am currently doing differential equations. A problem I am doing requires me to find the transfer function [X(s)/F(s)] and compute the characteristic roots. So far I have: X(s)/F(s) = (6s +4)/(s^2+14s+58) That is the transfer function but now...
  18. A

    Sum of Roots of x^3 - mx^2 + nx - 1 = 0

    If m, n, and 1 are non-zero roots of the equation x^3 - mx^2 + nx - 1 = 0, then find the sum of the roots This is what I did.. m, n, 1 are the roots. m and n not equal to 0 x^3 - mx^2 + nx - 1 = 0 f(m) = 0 --> m^3 - m^3 + mn - 1 1 = mn (1) f(1) = 1 - m + n - 1 = 0 ... m = n (2)...
  19. SOS2008

    News The Roots of Terrorism and US Foreign Policy

    In seeing various related topics in PF regarding the reasons for terrorism, solutions for terrorism, the effects of the Bush administration on our country and the world, and more recently nuclear proliferation via the Bush Doctrine, I thought I’d start this new thread, which also may provide...
  20. P

    Primitive Roots: Multiple Possibilities?

    Can a number have more than 1 primitive root? Thanks
  21. E

    Convergence of Nested Square Roots: Solving the Puzzle

    Hi, I came across this puzzle, see if you can solve it :smile: : \sqrt{1 + \sqrt{1 + 2\sqrt{1 + 3\sqrt{...}}}} = ?
  22. E

    A question of roots of riemann function

    let be the quotient: Lim_{x->c}\frac{\zeta(1-x)}{\zeta(x)} where x=c is a root of riemann function... then my question is if that limit is equal to exp(ik) with k any real constant...thanks... the limit is wehn x tends to c bieng c a root of riemann constant
  23. C

    Finding Roots of Complex Polynomials: General Formula and Exponential Form

    Hi all Jut had a question. How do I go about finding the general formula for roots of the complex poly {z}^{n}-a where a is another complex number. Do I just go {z}^{n}=a? :S so complicated this things! Thanks in advance!
  24. E

    Problem with roots of a function h(x)

    Let be the function h(x)=f(x)+g(x) we want to obtain the values of x so h(x)=0 and we have that f(x) and g(x) have the same roots (if a is so f(a)=0 then g(a)=0 too) so we have two types of roots: 1.-values of x that satisfy f(x)=-g(x) 2.values x that make f(x)=g(x)=0 then we make in the...
  25. C

    How Many Roots Exist for Complex Numbers Raised to Irrational Powers?

    There are n nth roots to every complex number (except zero). My question: How many "roots" are there when you take a complex number to an irrational or transcendental number. For that matter, how do we define raising a number to an irrational number? How do we define raising a number to a...
  26. B

    Equation satisfied by nth roots of unity

    Q. Fix n>= 1. If the nth roots of 1 are w_0,...,w_(n-1), show that they satisfy: \left( {z - \omega _0 } \right)\left( {z - \omega _1 } \right)...\left( {z - \omega _{n - 1} } \right) = z^n - 1 I tried considering z^n = 1. z^n = e^{i2\pi + 2k\pi i} \Rightarrow z =...
  27. A

    Factoring polymonial with complex roots

    This may be a bit silly but i forget how to factor this into complex factors: s^2 + 6s + 25 i know the answer is (s +3 - i4)(s +3 - j4) but how do i get that?
  28. cronxeh

    Auxiliary Equation with Imaginary Roots

    I was curious about what class would cover those types of Linear DE w Constant Coeff, particularly Hyperbolic Functions and exp z type of things. I remember my lecturer said back in Intro DE that we only covered first 2 types of Auxiliary Equations - real distinct roots and real repeated ones...
  29. T

    Complex roots problem (a proof by induction)

    Problem: If c_{1}, ..., c_{n} are the complex roots of a_{n}z^n + a_{n-1}z^{n-1} + ... + a_{1}z + a_{0} = 0 with a_{n} not 0 and S_{k} is the sum of the products of these roots taken k by k, then S_{k} = (-1)^k . \frac{a_{n-k}}{a_{n}}. Prove this by using induction. So for n = 3 this...
  30. L

    How is the distance to the x-axis related to the roots of quadratic equations?

    Hi, How is the roots of a quadratic equation related to the distance from the x-axis at where the root is - where ... ax^2+bx+c=0 and ... x = (-b +- SQRT(b^2-4ac))/2 Can someone help me to establish where this distance relationship to the x-axis and the root come from? Thx! LMA
  31. L

    Proving Odd Number of Real Roots in Cubic Equations

    Hi, A cubic equation has at least one real root. If it has more than one why are there always an odd number of real roots? Why not an even number of real roots? Can someone help me to prove this? Thx! LMA
  32. A

    What is the General Method for Deriving Cubic Roots?

    I've been trying to derive general solutions for cubic roots, i.e. the general solutions of (will Latex just work?) $ax^3+bx^2+cx+d=0$ I do not want to be shown the solutions - but does anyone know what direction to go into achieve this? I thought I'd found solutions at one point but...
  33. E

    Solving Complex Polynomial Equations

    Hi guys, can anyone tell me how I would go about solving this equation? : x^5 = x Rearranging it gives: x^5 - x = 0 But then I don't really know what to do next. I know just from looking at it and thinking about it that the roots should be x = 0, 1, -1, -i, i...but I need to be able to...
  34. H

    Extracting Square Roots in your head

    What are some good quick ways to Extract Square Roots in your head. I'm looking for a method that is very prescice and easy thanks, hopefully somebody helps me out
  35. E

    Finding roots without a calculator?

    hello. I was wanting to know how to raise a number to any power without using a calculator. More specifically, I was wanting to raise numbers to the .5 power, (and all the other roots, 1/2, 1/3, 1/4). How can this be done? <----------------------> My fellow 633|<5 :smile:
  36. A

    Primitive roots, specifically of 18

    this problem is annoying. I've found that the primitive roots of 9 are 2 and 5. since 2|18 it can't be a root. i know via some theorems in my book that if 5 is a primitive root of 3, then its a primitive root of 3^k, and also of 2*3^k. sorry about not using latex, shouldn't need it for...
  37. A

    Solve another trig eqn with square roots

    solve \sqrt2 \sin\theta= \sqrt3-\cos\theta algebraically for the domain 0<theta<2pi I know that the cos can be changed into 1-sin^2 theta but I don't know what to do after how do I get everything on the right hand side and simplify it?
  38. M

    Can x^n-a=0 have n real roots for n>2?

    In math class today, we were discussing quadratic residues, and one of the things that came up was the fact that x^n-a=0 has n roots. This just made me start thinking about real and complex roots. A question that I had was whether, given n>2, is it possible to have n real roots in...
  39. M

    What is the crazy integral that the professor and student are struggling with?

    I'm working with a professor on a project and we are going through a bunch of integrals in the "table of integrals series and products" and there is one that we cannot seem to get--the answer in the book is wrong after doing some numerical calculations, but we can't find a "solution" to the...
  40. I

    Properties of Roots of Real Numbers

    I have three problems that I can't seem to solve. I was wondering if anybody could help me or explain to me how to solve these. Note: * = multiplication. 1. (6^1/2 * 2^1/3)^6 2. ^4√7 + 2^4√1792 3. 3(X-4)^1/2 + 5 = 11
  41. D

    Estimating Square Roots and the Role of Calculators

    How can I estimate the value of sqrt. of a particular no. which is not a perfect square(e.g. 125) without using the calculator? Secondly how does the Calculator solve it? Does it use logrithms? If it does how does it solve them?
  42. S

    Find Roots of -5x^4-7x^2+10x+4 Equation

    We have to find the max/min of a derivative and we can't figure out how to find the roots of the function. The equation is y'=-5x^4-7x^2+10x+4. We tried factoring, but that won't work, the quadratic equation doesn't work, and we don't know how to solve for x. :cry:
  43. A

    What value of k gives no roots,one root, 2 roots?

    roots! HELP For what values of k does the equation x^2+k=kx-8 have two distinct roots, one real root, no real roots? convert into standard form first well x^2+k-kx+8 I don't know if i can simplify this further? and if i can't then what does a=? b=? and c=? I don't understand how to do...
  44. D

    What Values of a Allow a Polynomial to Have Reciprocal Roots?

    Hey guys can you help me solve this problem: Find all real numbers a with the property that the polynomial equation x^{10} + ax + 1 = 0 has a real solution r such that 1 / r is also a solution. Thank you for helping me :smile: Sry I have posted this problem once before, but nobody helped...
  45. quasar987

    Find all real roots of this polynomial

    How do we do this? I know how to find all RATIONNAL roots but what about the irrationnal ones? [tex]2x^5-5x^4-11x^3+23x^2+9x-18=0[/itex]
  46. E

    REALLY NEED HELP Solving for X with radicals/square roots

    Ok so I know that when you have radicals such as the following you only have one answer right?... x + 1 - 2(square root of [x+4]) = 0 ok so x = 5 right?... i don't know why but it just does... I can't solve it If i solve it It works looks like this: (squaring everything I...
  47. A

    Factorising x^3 + 216 to Include (x + 6)

    I need to factorise x^3 + 216 to include (x+6): (x + 6) \ (x^3 + 216) (lim where x approaches -6) I broke it down to (x + 6i)(x^2 - 36i) ... but that's no good.
  48. K

    Computing Complex Square Roots: A Function Theory Homework Problem

    I've got a homework problem from my function theory course that I never fully understood. It's getting hot again since the exams are nearing...please help :smile: It goes simply like this: Compute the Integral \int_{\vert z \vert=1}\frac{dz} {\sqrt{6 z^2-5 z +1}} The square root is chosen...
  49. L

    What Mathematical Significance Does the Roots Chain of Shadows Hold?

    Please look at the attached pdf http://www.geocities.com/complementarytheory/Roots-Chain.pdf . By this model we can see that √1 is the "shadow" of √2 and √2 is the "shadow" of √3. If we can conclude that √3 is the "shadow" of √4 ... and so on, then do you think that this "Chain of...
  50. Dissident Dan

    News Roots of Middle-Eastern Terrorism

    Why do we have anti-West terrorism stemming from the Middle East? Why do they have hatred for Westerners? I have heard the idea that it's becase they hate us for being great and successful and sugar and spice and are jealous to the point of nausea. I think that this is nothing but a...
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