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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 11.1.76b

{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 ⁻¹ x ≈ x

Guida verificata passo dopo passo
1
Identify the function and the approximation given: the function is \(f(x) = \sin^{-1}(x)\), and the approximation near zero is \(f(x) \approx x\).
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 that the error in a linear approximation can be estimated using the remainder term from Taylor's theorem. For \(\sin^{-1}(x)\) expanded at 0, the next term after \(x\) involves \(x^3\).
The second derivative of \(f(x) = \sin^{-1}(x)\) is \(f''(x) = \frac{x}{(1 - x^2)^{3/2}}\). Use this to find a bound on the error by evaluating or bounding \(|f''(c)|\) for some \(c\) between 0 and 0.2.
Use the Lagrange form of the remainder: the error \(R_2\) satisfies \(|R_2| \leq \frac{M}{3!} |x|^3\), where \(M\) is the maximum value of \(|f''(c)|\) on the interval \([0, 0.2]\). Calculate or estimate \(M\) and then compute the error bound.

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