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Ch. 11 - Power Series
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Non è quello che usi tu?Cambia libro di testo
Capitolo 11, Problema 11.1.69b

{Use of Tech} Small argument approximations Consider the following common approximations when x is near zero. 


b. Estimate f(0.2) and give a bound on the error in the approximation.


f(x) = sin x ≈ x

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1
Identify the function and the approximation given: the function is \(f(x) = \sin x\), and the approximation near zero is \(\sin x \approx x\).
To estimate \(f(0.2)\) using the approximation, substitute \(x = 0.2\) into the approximation: \(f(0.2) \approx 0.2\).
To find a bound on the error, recall the Taylor remainder theorem. The error in approximating \(\sin x\) by \(x\) near zero is given by the next term in the Taylor series expansion, which involves \(\frac{\cos c}{2} x^2\) for some \(c\) between 0 and \(x\).
Since \(|\cos c| \leq 1\) for all real \(c\), the maximum error bound is \(\left| R_2 \right| \leq \frac{|x|^3}{6}\), because the next term in the Taylor series for \(\sin x\) after \(x\) is \(-\frac{x^3}{3!}\).
Calculate the error bound by substituting \(x = 0.2\) into \(\frac{|x|^3}{6}\) to get the maximum possible error in the approximation.

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