A question about Taylor series expansion

In summary, the conversation discusses finding the Taylor series expansion for the function f(x)=x*e^(-x^2) about x=-1. The suggested method involves using the Hermite polynomials and their generating function to simplify the process. The relevant equations are the Hermite polynomials and their generating function, as well as the general method for determining Taylor series expansions for a function about a given point.
  • #1
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Homework Statement


Find the Taylor series expansion for f(x)=x*e^(-x^2) about x = -1


Homework Equations





The Attempt at a Solution


I have tried replacing x with (x-1) and f(x-1) = (x-1)*e^(-(x-1)^2).
Consider the power series for e^(-(x-1)^2) about x = 0, f(x-1) = (x-1)*(1/e+(2x-x^2)/e+(2x-x^2)^2/2!e+(2x-x^2)^3/3!e+...).
Let (x-1)*e^(-(x-1)^2) = A + Bx + Cx^2 + Dx^3 + Ex^4 + ...
So (x-1)*(1/e+(2x-x^2)/e+(2x-x^2)^2/2!e+(2x-x^2)^3/3!e+...) =A + Bx + Cx^2 + Dx^3 + Ex^4 + ...
Comparing x^n coefficients and I can get A, B,...
I don't know whether my method is correct and even it is correct ,it is too complicated.
I want an easier way to solve the problem.
Can anybody help me?
Thanks.
 
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  • #2
Sounds very complicated to me. I would suggest the following:

a) multiply you function by the fraction ([itex]\frac{-2}{-2}[/itex]). Now take a look at the numerator. Remind you of anything?

b) get familar with the Hermite Polynomials, more specifically, their generating function:
[tex]
H_r(x)=(-1)^r\,e^{x^2}\, \frac{d^r}{dx^r}(e^{-x^2})
[/tex]
 
  • #3
What are the Relevant equations?

In other words, how would you, in general, go about determining the Taylor expansion for some function f(x) about some point x=x0?
 

What is a Taylor series expansion?

A Taylor series expansion is a mathematical representation of a function as an infinite sum of terms. It is used to approximate a function at a certain point by adding up the values of the function and its derivatives at that point.

What is the purpose of a Taylor series expansion?

The purpose of a Taylor series expansion is to approximate a function at a certain point, allowing for more accurate calculations and predictions. It is commonly used in calculus and other fields of mathematics and science.

How is a Taylor series expansion calculated?

A Taylor series expansion is calculated by finding the coefficients of each term in the expansion. These coefficients are determined by taking the derivatives of the function at the point of expansion and plugging them into the expansion formula.

What is the difference between a Taylor series and a Maclaurin series?

A Taylor series is a generalization of the Maclaurin series, which is a special case where the point of expansion is at x=0. The Maclaurin series is often used to approximate functions near the origin, while a Taylor series can be used for any point.

What are the applications of Taylor series expansions?

Taylor series expansions have many applications in mathematics, physics, engineering, and other fields. They are used to approximate functions, solve differential equations, and analyze the behavior of systems. They are also used in computer graphics and numerical methods for solving problems.

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