MHB Fixed Point Theorem: Estimating x* With x9 & x10

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The discussion revolves around the fixed point theorem applied to the function $\varphi:[-1,1] \to [-1,1]$ with a contraction constant of $L=0.8$. It confirms that the sequence defined by $x_{n+1}=\varphi(x_{n})$ converges to a unique fixed point $x^{*}$ for any starting point $x_0$ in the interval. The user calculates the error bounds for the 10th approximation, finding that $|x_{10}-x^{*}|\leq 0.004$. The conclusion reached is that the first option, $|x_{10}-x^{*}|<0.005$, is correct. The discussion ends with a confirmation of the calculations and agreement on the findings.
evinda
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Hello! ;) I have a question.
Let $\varphi:[-1,1] \to [-1,1]$ with $L=0.8$ at $[-1,1]$, $\varphi$ has a unique fixed point $x^{*}$ and the sequence $(x_{n})$ with $x_{n+1}=\varphi(x_{n}) ,n=0,1,2,...$ is well defined and coverges to $x^{*}$ for any $x_{0} \in [-1,1]$.Then if the 9th approximation is $x_{9}=0.37282$ and the 10th is $x_{10}=0.37382$,we can say for sure that:
1) $|x_{10}-x^{*}|<0.005$
2) $|x_{10}-x^{*}|<0.001$
3) $|x_{10}-x^{*}|<0.002$

I used the formula $|x_{10}-x^{*}|\leq\frac{L}{1-L}|x_{n}-x_{n-1}|$ and found that $|x_{10}-x^{*}|\leq 0.004$.Is this right?So,is 1) the right answer? (Thinking)
 
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evinda said:
Hello! ;) I have a question.
Let $\varphi:[-1,1] \to [-1,1]$ with $L=0.8$ at $[-1,1]$, $\varphi$ has a unique fixed point $x^{*}$ and the sequence $(x_{n})$ with $x_{n+1}=\varphi(x_{n}) ,n=0,1,2,...$ is well defined and coverges to $x^{*}$ for any $x_{0} \in [-1,1]$.Then if the 9th approximation is $x_{9}=0.37282$ and the 10th is $x_{10}=0.37382$,we can say for sure that:
1) $|x_{10}-x^{*}|<0.005$
2) $|x_{10}-x^{*}|<0.001$
3) $|x_{10}-x^{*}|<0.002$

I used the formula $|x_{10}-x^{*}|\leq\frac{L}{1-L}|x_{n}-x_{n-1}|$ and found that $|x_{10}-x^{*}|\leq 0.004$.Is this right?So,is 1) the right answer? (Thinking)

Yep. All correct!
 
I like Serena said:
Yep. All correct!

Great!Thank you! (Happy)
 
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