Using Taylor's Theorem to approximate

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    Approximate Theorem
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Discussion Overview

The discussion revolves around the application of Taylor's Theorem to approximate the value of the exponential function e^x, particularly at x=0 and nearby values. Participants explore the use of Taylor series for approximation and its implications.

Discussion Character

  • Exploratory
  • Mathematical reasoning
  • Homework-related

Main Points Raised

  • One participant inquires about using Taylor's Theorem to approximate e^x at x=0 and questions the theorem's purpose if not for approximation.
  • Another participant points out that e^0 is known to be 1, suggesting that approximation may be more relevant for values like e^0.01 or e^0.17671234.
  • A participant requests an example of how Taylor approximations work, indicating a desire for clarification on the method.
  • One participant provides a specific approximation for e^0.001 using the Taylor series expansion, demonstrating the application of the theorem.
  • Another participant elaborates on approximating e^0.01 by forming the Taylor series about the origin, detailing the calculations and results.

Areas of Agreement / Disagreement

Participants generally agree on the utility of Taylor's Theorem for approximating values of the exponential function, though there is some debate about the necessity of approximating e^0 specifically.

Contextual Notes

Some assumptions regarding the use of Taylor series and the choice of expansion point may not be explicitly stated. The discussion does not resolve whether approximating e^0 is necessary or beneficial.

Who May Find This Useful

Readers interested in mathematical approximations, particularly those studying calculus or the properties of exponential functions, may find this discussion relevant.

Shameel
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Hi Guys,

Is there any whay I can use the following theorem to approximate the value of e^x at x=0?

[tex]f(x) = f(a) + f'(a)(x - a) + \frac{f''(a)}{2!}(x - a)^2 + ...[/tex]

If the above function is not used for approximation, then what is it used to do?

Thanks heaps :smile: :smile: :smile:
 
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Why bother approximating [tex]e^{0}?[/tex]
You know what it is: [tex]e^{0}=1[/tex]

However, since you know that, you are now in a position to approximate with only a couple of terms in the Taylor series function values like [tex]e^{0.01}, e^{0.17671234}[/tex]
 
arildno said:
Why bother approximating [tex]e^{0}?[/tex]
You know what it is: [tex]e^{0}=1[/tex]

However, since you know that, you are now in a position to approximate with only a couple of terms in the Taylor series function values like [tex]e^{0.01}, e^{0.17671234}[/tex]
I am a n00b. Could you give me an example how Taylor approximations work?
 
Sure.

[tex]e^{0.001}\simeq e^{0}+1(0.001-0)+\frac{1}{2}(0.001-0)^{2}[/tex]

Daniel.
 
Let us try to approximate [tex]e^{0.01}[/tex] by forming the Taylor series about the origin:
Then, we have:
[tex]e^{x}=f(x)\approx{f}(0)+f'(0)(x-0)+\frac{1}{2}f''(0)(x-0)^{2}[/tex]
where I've retained the 3 first terms in the Taylor series.
But, now, we have:
[tex]f(0)=e^{0}=1,f'(0)=e^{0}=1,f''(0)=e^{0}=1[/tex]
since the derivative of the exponential function is itself
Thus, we have:
[tex]e^{0.01}\approx{1}+1*(0.01-0)+\frac{1}{2}*1*(0.01-0)^{2}=1+\frac{1}{100}+\frac{5}{100000}=1.01005[/tex]
 

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