Taylor Definition and 878 Threads

  1. 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...
  2. C

    What is the proof of the Taylor Theorem in n variables?

    Hello, guys. I am studying the Taylor Theorem for functions of n variables and in one book I've found a proof based on the lemma that I am copying here. I am having some trouble in following its proof so I seek your kind assistance. The lemma rests on two items: the definition of a function...
  3. C

    What is the Taylor expansion for 1/(1-exp(-1))?

    Hi How do you expand (1-exp(-1))^-1 as Taylor series Callisto
  4. D

    Taylor differentition polynomials?

    taylor differentition polynomials? hi got a question here that involves this extremely difficult question anyone that can point me in the right direction on what to do will be most appreciated :) Find Exactly the tayor polynomial of degree 4 f(x) = cos ( pi*x / 6 ) about x=-1 i know...
  5. 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...
  6. 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...
  7. 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...
  8. 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...
  9. 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.
  10. S

    Taylor Approximation Help - Find n Given x, a, ErrorBound

    Hi, I'm having trouble doing my work where I have to find the Taylor Approximation of function. My real work is the program this thing when the function, x, a, and ErrorBound is given. I don't knwo what to do with the ErrorBound to get n, where n is the number of terms. do i make any sense...
  11. S

    Taylor Polynomial of 6th Degree for ln(1-x^2) with c=0

    I just want to check my answer. The question asks for the Taylor polynomial of degree 6 for ln(1-x^2) for -1<x<1 with c=0. I got tired after differentiating 6 times so I'm worried I made some mistakes along the way. The question also said: hint: evaluate the derivatives using the formula...
  12. T

    Proving Pn(x^2) as the 4n+2-nd Taylor Polynomial of sin(x^2) using Rn(x) Limits

    Show that Pn(x^2) is the 4n+2-nd Taylor polynomial of sin(x^2) by showing that \lim_{n\rightarrow infinity} R2n+1(x^2) = 0. note that Rn(x) represents the remainder I'm stuck on this question, can anyone help me please?
  13. 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} -...
  14. quasar987

    Taylor Expansion for Large R: Showing V Approximates $\frac{\pi a^2 \sigma}{R}$

    V = 2\pi \sigma(\sqrt{R^2+a^2}-R) Show that for large R, V \approx \frac{\pi a^2 \sigma}{R} I figured if I could develop the MacLaurin serie with respect to an expression in R such that when R is very large, this expression is near zero, then the first 1 or 2 terms should be a fairly...
  15. W

    Can someone help me understand Taylor and MacLaurin series?

    I am having difficulty understanding Taylor and MacLaurin series. I need someone to go through step by step and explain a problem from beginning to end. You could use the function f(x) = cos x. Also, could someone find the MacLaurin series of 1/(x^2 + 4) ? I just don't understand the basics of...
  16. 3

    Finding Taylor Polynomial for f(x) = (1+x)^{2/3}

    1. Let f(x) = (1+x)^{2/3} (a) find the taylor polynomial T_2(x) of f expanded about a = 0. i got 1 + (1/3)x - (1/9)x^{2} For the rest, i have no idea how to do...any help would be greatly appreciated. (b) For the givven f write the lagrange remainder formula for the error term...
  17. D

    Mathematica Obtain 8th Degree Taylor Polynomial for Sqrt(x) with Mathematica

    In order to obtain with the aid of Mathematica, say, an 8-th degree Taylor polynomial of \sqrt{x} centered at 4 , I use the following command: Normal[Series[Sqrt[x], {x, 4, 8}]] and I get \sqrt{x} \approx 2 + \frac{1}{2^2} \left( x - 4 \right) - \frac{1}{2^6} \left( x - 4 \right) ^2...
  18. D

    Taylor Series/Radius of Convergence - I just need a hint

    Consider the following: f(x) = 1 + x + x^2 = 7 + 5 (x-2) + (x-2)^2 which is a Taylor series centered at 2. My question is: what is the radius of convergence? The answer in my book is R=\infty , but take a look at this: f(x) = 7 + 5 (x-2) + (x-2)^2 = \sum _{n=0} ^{\infty} b_n (x-2)^n...
  19. L

    Confused about taylor approximation

    I am a bit confused about taylor approximation. Taylor around x_0 yields f(x) = f(x_0) + f'(x_0)(x-x_0) + O(x^2) which is the tangent of f in x_0, where f'(x) = f'(x_0) + f''(x_0)(x-x_0) + O(x^2) which adds up to f(x) &=& f(x_0) + (f'(x_0) + f''(x_0)(x-x_0) +...
  20. D

    What's the purpose of Taylor Polynomials?

    I don't get it. I use it to approximate f for some x, but the formula for Taylor Polynomials already has f in it?
  21. 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
  22. 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)...
  23. 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 -...
  24. H

    Taylor Polynomials: Approximating f(x) and f'(x)

    Let f be a function that has derivatives of all orders for all real numbers. Assume f(1)=3, f'(1)=-2, f"(1)=2, and f'''(1)=4 a. Write the second-degree Taylor polynomial for f about x=1 and use it to approximate f(0.7). b. Write the third-degree Taylor polynomial for f about x=1 and use it...
  25. 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...
  26. 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...
  27. R

    How does Taylor series help expand the function 1/sqrt(1-x^2)?

    basic taylor expansion... Hi, could some one explain how i could use the taylor series to expand out: f(x)= 1/sqrt(1-x^2) Any help would be appreciated, thanks.
  28. 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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