Taylor series Definition and 480 Threads

  1. T

    Can the Taylor Series of Analytic Functions be Proven?

    i'm having a hard time understanding taylor series and why it works and how it works. if someone could please explain it to me that would be great. My teacher explained it in class but he goes so fast that i have no idea what he's saying. he did give us some practice problems but if i have no...
  2. M

    What Are the Real Benefits of Using Taylor Series for Function Approximations?

    hi everyone, I am just learning the taylor series at school. I am slightly confused. in my textbook, one of hte exercises is to find hte nth degree taylor polynomial of x^4 about a=-1. n is 4 in this case so this gives me a long polynomial. i understand that inputting any x value into this...
  3. V

    How Does Taylor Series Approximation Determine Electric Potential Over Distance?

    The electric potential V at a distance R along the axis perpendicular to the center of a charged disc with radius a and constant charge density d is give by V = 2pi*d*(SQRT(R^2 +a^2) - R) Show that for large R V = pi*a^2*d / R This is what I have done so far... V = 2pi*d *...
  4. T

    How Can Taylor Series Approximate Second Derivatives?

    I am supposed to prove using taylor series the following: \frac{d^2\Psi}{dx^2} \approx \frac{1}{h^2}[\Psi (x+h) - 2\Psi(x) + \Psi (x-h)] where x is the point where the derivative is evaluated and h is a small quantity. what i have done is used: f(x+h)= f(x) + f'(x) h +...
  5. K

    Expanding f(x,y) with Double Taylor Series

    Let be an analytic function f(x,y) so we want to take its Taylor series, my question is if we can do this: -First we expand f(x,y) on powers of y considering x a constant so: f(x,y)= \sum_{n=0}^{\infty}a_{n} (x)y^{n} and then we expand a(n,x) for every n into powers of x so we have...
  6. C

    Finding the 2005th Derivative with Taylor Series for Inverse Tan Function

    I have got a question here that puzzles me. How do I use TAYLOR SERIES to find the 2005th derivative for the function when x=0 for the following function: f(x) = inverse tan [(1+x)/(1-x)] Part (1) I was hinted that differentiating inverse tan x is = 1/(1+x^2). Part (2) After which, I need to...
  7. C

    Taylor Series Approximation for Solving Initial Value Problems

    With a simple ODE like \frac{ds}{dt} = 10 - 9.8t and you're given an initial condition of s(0) = 1, when doing the approximation would s'(0) = 10 - 9.8(0), s'' = ... etc?
  8. A

    Starting a Taylor series problem, .

    Compute the Taylor series for f(x)= sq root (x) about x=1. Determine where the series sconverges absolutely, converges conditionally, and diverges. Hint: 2(k!)=2*4*6...(2k-2)*2k. Also 1<2, 3<4, 5<6,..., 2k-1<2k should help you out with a comparision.
  9. E

    Complex analysis taylor series Q

    hi, I'm wondering if someone can help me out with this question: "What are the first two non-zero terms of the Taylor series f(z) = \frac {sin(z)} {1 - z^4} expanded about z = 0. (Don't use any differentiation. Just cross multiply and do mental arithmetic)" I know the formula for...
  10. T

    Taylor Series for ln(1-x): Get Help Now

    may i know from ln(1-x) how to become - [infinity (sum) k=1] x^k / k ? pls help
  11. P

    Taylor series homework problem

    Dear friends, I have a question on a taylor series, that is this one: A·e^(i (x)) That is: cos (x)+ i sin (x) becouse of the taylor's. But, is this wrong? A·e^(v (x)) = cos (x)+ v sin (x) (v is a vector). Tks.
  12. A

    Taylor Series to x places of decimals

    Hi all, here's the problem: [FONT="Arial"][FONT="Century Gothic"]given: tan^(-1)= x - x^3/3 + x^5/5 using the result tan^(-1) (1)= pi/4 how many terms of the series are needed to calculate pi to ten places of decimals? note: this is supposed to say tan^(-1) and tan^(-1)[1]...
  13. N

    What did I do wrong in my Taylor Series Expansion for y=kcosh(x/k)?

    y=kcosh(x/k) = k(e^(x/w) + e^(-x/k)) y ~ k[1 + x/k + (1/2!)(x^2/k^2) + (1/3!)(x^3/k^3)] +...+ k[1 - x/k +(1/2!)(x^2/k^2) - (1/3!)(x^3/k^3) +...] All odd terms except 1 cancel out. So we are left with y = k [2 + (2/2!)(x^2/k^2) + (2/4!)(x^4/k^4) + (2/6!)(x^6/k^6) +...] I've been...
  14. A

    How Can You Derive the Taylor Series of 1/sqrt(cosx) Using the Series for cosx?

    Is there a way to get the Taylor series of 1/sqrt(cosx), without using the direct f(x)=f(0)+xf'(0)+(x^2/2!)f''(0)+(x^3/3!)f'''(0)... form, just by manipulating it if you already know the series for cosx?
  15. P

    Solving Differential Equations with Simple Taylor Series Method

    Hi, I was reading this math book once... and it had a method for solving differential equations of 1st (And maybe 2nd? I don't remember) order by using simple Taylor series... I didn't even have to understand much of what was going on, except that I followed some simple rule and I ended up...
  16. B

    Understanding Taylor Series Error & Degrees of Variables

    Hi, can someone explain me the relation between the degree of a taylor series (TS) and the error. It is for my class of numerical method, and I do not find a response to my question in my textbook. I mean when we have a function Q with two variables x and y,and we use a version of TS to...
  17. B

    How Does the Degree of a Taylor Series Affect Error in Numerical Methods?

    Hi, can someone explain me the relation between the degree of a taylor series (TS) and the error. It is for my class of numerical method, and I do not find a response to my question in my textbook. I mean when we have a function Q with two variables x and y,and we use a version of TS to...
  18. B

    Solving Taylor Series Problem with m-th Derivative Bound

    Hi , I have some difficulties to solve this problem. It is from my numerical methods class but the problem is about taylor series: It is known that for 4 < x < 6, the absolute value of the m-th derivative of a certain function f(x) is bounded by m times the absolute value of the quadratic...
  19. M

    Taylor series expansion question

    Hi, I have a question about Taylor series: I know that for a function f(x), you can expand it about a point x=a, which is given by: f(x) = f(a) + f'(a)(x - a) + \frac{f''(a)}{2!}(x - a)^2 + ... but I would like to do it for f(x+a) instead of f(x), and expand it about the very same point...
  20. X

    Taylor Series Expansion for z^i at z=1+i: First Three Terms

    I need to find the first three terms of this series. Am I correct in saying z^i = exp(i*Log(z)), then using the taylor series for e^z, giving me: (i*Log(z)) - 1/2*(Log(z))^2 - i/6*(Log(z))^3 + 1/24*(Log(z))^4 + ... I haven't worked it out, but this seems to mean that the coefficients...
  21. R

    Taylor Series for Showing B_{x}(x+dx)-B_{x}(x) Approximation

    How do i show that B_{x}(x+dx,y,z)-B_{x}(x,y,z)\approx \frac{\partial B_{x}(x,y,z)}{\partial x} dx using a Taylor series to the first term. Using a Taylor series does B(x) = B(a) + B'(a)(x-a)? In that case what would B(x+dx) be and how can i obtain the desired result from this? Thanks in...
  22. P

    Finding Taylor Series of Functions - Tips to Make it Easier

    I was wondering if someone can give me some tips for finding the taylor series of functions. For example this was a test question we had: Find the taylor series of f(x)=ln(x) about x=e I know how to start it off but I get confused halfway through and can't seem to figure out what to do...
  23. A

    How Is the Full Taylor Series Derived Beyond Its Linear Approximation?

    I understand what a linear approximation, and how it is derived using the point-slope formula: f(x)\approx f(a)+f'(a)(x-a) These are the first three terms of a Taylor series, so I was wondering how the rest was derived? Thanks for your help.
  24. D

    Taylor series exp. & a couple of other questions

    Problem Find the sum of the series s(x) = \sum _{n=1} ^{\infty} \frac{1}{2^{n}} \tan \frac{x}{2^n} Solution If s(x) = \sum _{n=1} ^{\infty} \frac{1}{2^{n}} \tan \frac{x}{2^n} = \frac{x}{3} + \frac{x^3}{45} + \frac{2x^5}{945} + \dotsb \cot x = \frac{1}{x} - \frac{x}{3} -...
  25. D

    Taylor Series Problem Solved: Coefficient of x^7

    Help me out with this Taylor series problem: The Taylor series for sin x about x = 0 is x-x^3/3!+x^5/5!-... If f is a function such that f '(x)=sin(x^2), then the coefficient of x^7 in the Taylor series for f(x) about x=0 is? thanks
  26. A

    Dummy Variables in Taylor Series

    Taylor Series in x-a Hi, I've got a question about the use of dummy variables in Taylor Series. We are asked to expand: g(x) = xlnx In terms of (x-2). So originally, I used a dummy variable approach to try and find an answer. Let t = x-2, so x = t+2. g(x) = (t+2)ln(2+t)...
  27. dduardo

    Taylor Series Solution for y'' = e^y at x=0, y(0)=0, y'(0)=-1

    This problem has been bugging me and I can't seem to figure it out: y'' = e^y where y(0)= 0 and y'(0)= -1 I'm supposed to get the first 6 nonzero terms I know the form is: y(x) = y(0) + y'(0)x/1! + y''(0)x^2/2! + y'''(0)x^3/3! +... and I know the first two terms are y(x) = 0 -...
  28. T

    Taylor Series for ln(x+1) at x=1

    Find the 4th term of the Taylor series centerd at x=1 for f(x)=ln(x+1) f(x)=ln(1=x) f'(x)=(1+x)^-1 f"(x)=(-1)[(1+x)^-2] f"'(x)=(2)[(1+x)^-3] f""(x)=-6[(1+x)^-4)] Plug in 1: .6931 .5 -.25 .25 -.375 What do I do next? (Also, is the 4th term the 4th term starting with f(x)? or the...
  29. C

    Taylor series with partial derivatives

    We were gievn a question in tutorial last week asking us to calculate the Taylor series of the function f(x,y) = e^(x^(2) + y^(2)) to second order in h and k about the point x=0, y=0 I've got the forumla here with all the h's and k's in it and have it written down, but it's actually how to...
  30. K

    What is the Taylor series for i^i?

    I'm having some problems expanding i^i, could anyone help? I know it becomes a real number somehow, and I'm familiar with the e^(i * pi) expansion, but is the i^i done in the same way?
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