Skip to main content
Ch. 11 - Power Series
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243당신이 사용하는 게 아니라요?교과서 변경
11장, 문제 11.1.56

{Use of Tech} Maximum error Use the remainder term to find a bound on the error in the following approximations on the given interval. Error bounds are not unique.


tan x ≈ x on [−π/6, π/6]

검증된 단계별 안내
1
Identify the function and the approximation: here, the function is \(f(x) = \tan x\) and the approximation is \(f(x) \approx x\) on the interval \(\left[-\frac{\pi}{6}, \frac{\pi}{6}\right]\).
Recognize that the approximation \(\tan x \approx x\) is the first-degree Taylor polynomial of \(\tan x\) centered at 0, so the error can be estimated using the Lagrange remainder term for the Taylor series expansion.
Recall the Lagrange remainder formula for the Taylor polynomial of degree 1 centered at 0: the error \(R_1(x)\) satisfies \[R_1(x) = \frac{f^{(2)}(c)}{2!} x^2\] for some \(c\) between 0 and \(x\).
Calculate the second derivative of \(f(x) = \tan x\). First, \(f'(x) = \sec^2 x\), then \[f^{(2)}(x) = \frac{d}{dx} (\sec^2 x) = 2 \sec^2 x \tan x.\]
To find the error bound, determine the maximum value of \(|f^{(2)}(c)|\) on the interval \(\left[-\frac{\pi}{6}, \frac{\pi}{6}\right]\), then use it in the remainder formula: \[|R_1(x)| \leq \frac{\max_{c \in [-\frac{\pi}{6}, \frac{\pi}{6}]} |f^{(2)}(c)|}{2} x^2.\]

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
3m
도움이 되었나요?

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Taylor Polynomial Approximation

A Taylor polynomial approximates a function near a point using derivatives at that point. For tan x near 0, the linear approximation is tan x ≈ x, which is the first-degree Taylor polynomial. Understanding this helps in estimating how close the approximation is to the actual function.
추천 영상:
07:00
Taylor Polynomials

Remainder Term (Lagrange Form)

The remainder term quantifies the error between the function and its Taylor polynomial approximation. The Lagrange form expresses this error using a higher-order derivative evaluated at some point in the interval, providing a bound on the maximum possible error.
추천 영상:
가이드 코스
06:32
Alternating Series Remainder

Error Bound on an Interval

To find an error bound on [−π/6, π/6], we evaluate the maximum value of the relevant derivative in that interval. This maximum derivative value, combined with the remainder formula, gives a guaranteed upper limit on the approximation error over the entire interval.
추천 영상:
가이드 코스
04:57
Determining Error and Relative Error