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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 11.1.14

Use of Tech Linear and quadratic approximation


a. Find the linear approximating polynomial for the following functions centered at the given point a.


b. Find the quadratic approximating polynomial for the following functions centered at a.


c Use the polynomials obtained in parts (a) and (b) to approximate the given quantity.


f(x) = cos x, a = π/4; approximate cos (0.24π)

Guida verificata passo dopo passo
1
Step 1: Identify the function and the center point. Here, the function is \(f(x) = \cos x\) and the center point is \(a = \frac{\pi}{4}\).
Step 2: Find the value of the function and its derivatives at the center point \(a\). Calculate \(f(a) = \cos\left(\frac{\pi}{4}\right)\), the first derivative \(f'(x) = -\sin x\) and evaluate \(f'(a) = -\sin\left(\frac{\pi}{4}\right)\), and the second derivative \(f''(x) = -\cos x\) and evaluate \(f''(a) = -\cos\left(\frac{\pi}{4}\right)\).
Step 3: Write the linear approximating polynomial (the first-degree Taylor polynomial) centered at \(a\): \(L(x) = f(a) + f'(a)(x - a)\).
Step 4: Write the quadratic approximating polynomial (the second-degree Taylor polynomial) centered at \(a\): \(Q(x) = f(a) + f'(a)(x - a) + \frac{f''(a)}{2}(x - a)^2\).
Step 5: Use the polynomials \(L(x)\) and \(Q(x)\) to approximate \(\cos(0.24\pi)\) by substituting \(x = 0.24\pi\) into each polynomial.

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