11. 1.33-T nth order Taylor polynomials - - centered at a=100, n=0

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Discussion Overview

The discussion revolves around finding the nth order Taylor polynomials for the function \( f(x) = \sqrt{x} \) centered at \( a = 100 \) for \( n = 0, 1, 2 \). Participants explore the calculations involved in determining these polynomials, focusing on the mathematical reasoning and notation used in the process.

Discussion Character

  • Mathematical reasoning
  • Technical explanation
  • Homework-related

Main Points Raised

  • One participant calculates \( P_0(x) \) and confirms it as 10, asking for validation of their result.
  • Another participant agrees with the correctness of \( P_0(x) \) and prompts for the calculations of \( P_1(x) \) and \( P_2(x) \).
  • A third participant provides calculations for \( P_1(x) \) and \( P_2(x) \), detailing the derivatives and their evaluations at \( x = 100 \). They present the final polynomial approximation as \( \sqrt{x} \approx 10 + \frac{1}{20}(x-100) - \frac{1}{8000}(x-100)^2 \).
  • Another participant critiques the notation used for \( P_n(x) \) and rephrases the expressions for \( P_1(x) \) and \( P_2(x) \), suggesting a different arrangement of terms.
  • A final participant reiterates the calculations for \( P_1(x) \) and \( P_2(x) \), confirming their results and questioning if they are ready for presentation as an example.

Areas of Agreement / Disagreement

There is general agreement on the correctness of \( P_0(x) \). However, there are differing views on the notation and arrangement of terms in \( P_1(x) \) and \( P_2(x) \), indicating that the discussion remains somewhat contested regarding these aspects.

Contextual Notes

Participants express uncertainty about the notation used for the Taylor polynomials and the arrangement of terms in the final expressions, which may depend on personal preferences or conventions in mathematical writing.

karush
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$\tiny {11. 1.33-T} $
$\textsf{Find the nth order Taylor polynomials of the given function centered at a=100, for $n=0, 1, 2.$}\\$
$$\displaystyle f(x)=\sqrt{x}$$
$\textsf{using}\\$
$$P_n\left(x\right)
\approx\sum\limits_{k=0}^{n}
\frac{f^{(k)}\left(a\right)}{k!}(x-a)^k$$
$\textsf{n=0}\\$
\begin{align}
f^0(x)&= \displaystyle f(x)=\sqrt{x}
\therefore f^0(100)=10\\
P_0\left(x\right)&=\frac{f^0(100)}{0!}(x-100)^{0}= 10
\end{align}
$\textit{just seeing if this is correct 🍮}$
 
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karush said:
$\tiny {11. 1.33-T} $
$\textsf{Find the nth order Taylor polynomials of the given function centered at a=100, for $n=0, 1, 2.$}\\$
$$\displaystyle f(x)=\sqrt{x}$$
$\textsf{using}\\$
$$P_n\left(x\right)
\approx\sum\limits_{k=0}^{n}
\frac{f^{(k)}\left(a\right)}{k!}(x-a)^k$$
$\textsf{n=0}\\$
\begin{align}
f^0(x)&= \displaystyle f(x)=\sqrt{x}
\therefore f^0(100)=10\\
P_0\left(x\right)&=\frac{f^0(100)}{0!}(x-100)^{0}= 10
\end{align}
$\textit{just seeing if this is correct 🍮}$

It's correct for P0, now you need P1 and P2...
 
$\tiny {11. 1.33-T} $
$\textsf{Find the nth order Taylor polynomials of the given function centered at a=100, for $n=0, 1, 2.$}\\$
$$\displaystyle f(x)=\sqrt{x}$$
$\textsf{using}\\$
$$P_n\left(x\right)
\approx\sum\limits_{k=0}^{n}
\frac{f^{(k)}\left(a\right)}{k!}(x-a)^k$$
$\textsf{n=0}\\$
\begin{align}
f^0(x)&= \displaystyle f(x)=\sqrt{x}
\therefore f^0(100)=10\\
P_0\left(x\right)&=\frac{f^0(100)}{0!}(x-100)^{0}= 10
\end{align}
$\textsf{n=1}\\$
\begin{align}
f^1(x)&= \displaystyle f(x)=\frac{1}{2\sqrt{x}}
\therefore f^1(100)=\frac{1}{20}\\
P_0\left(x\right)&=\frac{f^1(100)}{1!}(x-100)^{1}
= \frac{1}{20}(x-100)
\end{align}
$\textsf{n=2}\\$
\begin{align}
f^2(x)&= \displaystyle f(x)=-\frac{1}{4x^{3/2}}
\therefore f^2(100)=\frac{1}{4000}\\
P_0\left(x\right)&=\frac{f^2(100)}{2!}(x-100)^{2}
= \frac{1}{8000}(x-100)^2
\end{align}
$\textsf{so finally}\\$
$$\sqrt{x}
\approx 10 + \frac{1}{20}(x-100)-\frac{1}{8000}(x-100)^2$$

$\textit{suggestions}$☕
 
Last edited:
I think you are misusing the notation "[math]P_n(x)[/math]". Yes, P_0(x)= 10 because f(100)= 10. And the next term in the Taylor's expansion is [math]\frac{1}{20}[/math] so that P_1(x)= \frac{1}{20}(x- 100)+ 10. Then the next term is [math]-\frac{1}{8000}(x- 100)^2[/math] so [math]P_2(x)= -\frac{1}{8000}(x- 100)^2+ \frac{1}{20}(x- 100)+ 10[/math].
 
$\tiny {11. 1.33-T} $
$\textsf{Find the nth order Taylor polynomials of the given function centered at a=100, for $n=0, 1, 2.$}\\$
$$\displaystyle f(x)=\sqrt{x}$$
$\textsf{using}\\$
$$P_n\left(x\right)
\approx\sum\limits_{k=0}^{n}
\frac{f^{(k)}\left(a\right)}{k!}(x-a)^k$$
$\textsf{n=0}\\$
\begin{align}
f^0(x)&= \displaystyle f(x)=\sqrt{x}
\therefore f^0(100)=10\\
P_0\left(x\right)&=\frac{f^0(100)}{0!}(x-100)^{0}= 10
\end{align}
$\textsf{n=1}\\$
\begin{align}
f^1(x)&= \displaystyle f(x)=\frac{1}{2\sqrt{x}}
\therefore f^1(100)=\frac{1}{20}\\
P_1\left(x\right)&=\frac{f^1(100)}{1!}(x-100)^{1}
= \frac{1}{20}(x-100)+10
\end{align}
$\textsf{n=2}\\$
\begin{align}
f^2(x)&= \displaystyle f(x)=-\frac{1}{4x^{3/2}}
\therefore f^2(100)=\frac{1}{4000}\\
P_2\left(x\right)&=\frac{f^2(100)}{2!}(x-100)^{2}
= \frac{1}{8000}(x-100)^2+\frac{1}{20}(x-100)+10
\end{align}

$\textit{so would this be 'example' ready?}$😎
 

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