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

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SUMMARY

The discussion focuses on calculating the nth order Taylor polynomials for the function \( f(x) = \sqrt{x} \) centered at \( a = 100 \) for \( n = 0, 1, 2 \). The calculations confirm that \( P_0(x) = 10 \), \( P_1(x) = \frac{1}{20}(x-100) + 10 \), and \( P_2(x) = -\frac{1}{8000}(x-100)^2 + \frac{1}{20}(x-100) + 10 \). The participants validate the correctness of these polynomial expressions and clarify the notation used for \( P_n(x) \).

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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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