Chapter 11: Problem 25
Find Maclaurin's formula with remainder for the given \(f(x)\) and \(n\). $$ f(x)=1 /(x-1)^{2}, \quad n=5 $$
Short Answer
Expert verified
The Maclaurin polynomial is \( P_5(x) = 1 - 2x + 3x^2 - 4x^3 + 5x^4 - 6x^5 \) with remainder \( R_5(x) = \frac{5040(c-1)^{-8}}{6!} x^6 \).
Step by step solution
01
Understand the Problem
We need to find the Maclaurin series expansion for the function \( f(x) = \frac{1}{(x-1)^2} \) up to \( n = 5 \) with the remainder term. Recall that Maclaurin's series is the Taylor series around \( a = 0 \).
02
Calculate the Derivatives
Compute the first few derivatives of \( f(x) = \frac{1}{(x-1)^2} \).1. \( f(x) = (x-1)^{-2} \)2. \( f'(x) = -2(x-1)^{-3} \)3. \( f''(x) = 6(x-1)^{-4} \)4. \( f'''(x) = -24(x-1)^{-5} \)5. \( f^{(4)}(x) = 120(x-1)^{-6} \)6. \( f^{(5)}(x) = -720(x-1)^{-7} \)
03
Evaluate Derivatives at a=0
Compute the derivative values at \( x = 0 \), since we are working with the Maclaurin series.- \( f(0) = 1 \)- \( f'(0) = -2 \)- \( f''(0) = 6 \)- \( f'''(0) = -24 \)- \( f^{(4)}(0) = 120 \)- \( f^{(5)}(0) = -720 \)
04
Construct the Maclaurin Polynomial
Use the derivatives calculated at \( x = 0 \) to construct the polynomial:\[P_5(x) = f(0) + \frac{f'(0)}{1!}x + \frac{f''(0)}{2!}x^2 + \frac{f'''(0)}{3!}x^3 + \frac{f^{(4)}(0)}{4!}x^4 + \frac{f^{(5)}(0)}{5!}x^5\]Replacing the values:\[P_5(x) = 1 - 2x + 3x^2 - 4x^3 + 5x^4 - 6x^5\]
05
Determine the Remainder
For Maclaurin series, the remainder term \( R_n(x) \) is given by:\[R_5(x) = \frac{f^{(6)}(c)}{6!} x^6\]where \( c \) is some value between 0 and \( x \).Compute \( f^{(6)}(x) = 5040(x-1)^{-8} \) and evaluate at some \( c \) to approximate or identify the behavior of the remainder explicitly.
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Taylor series
A Taylor series is a way to represent a function as an infinite sum of terms calculated from the derivatives of the function at a specific point. This mathematical technique is particularly useful in calculus for approximating complex functions with a simpler polynomial function.
- The Taylor series centered at a point, usually denoted as 'a', requires knowing the function's derivatives at that point.
- A special case of the Taylor series centered at zero is known as the Maclaurin series.
- The general formula for a Taylor series is:\[T(x) = f(a) + \frac{f'(a)}{1!}(x-a) + \frac{f''(a)}{2!}(x-a)^2 + \ldots\]
calculus
Calculus, a branch of mathematics, deals with the study of change. It's fundamentally composed of two parts: differentiation and integration.
- Differentiation: The process of finding derivatives, which give us the rate at which a quantity changes.
- Integration: The reverse of differentiation; it allows us to find the area under curves.
derivatives
Derivatives are a cornerstone in calculus, serving as a measure of how a function changes as its input changes. In simpler terms, a derivative provides the rate of change or the slope of the function at a specific point.
The process of finding a derivative is called differentiation. For any function, the first derivative gives us the slope of the tangent line at any point, and higher-order derivatives provide further insights into the function, such as finding concavity and inflection points.
The process of finding a derivative is called differentiation. For any function, the first derivative gives us the slope of the tangent line at any point, and higher-order derivatives provide further insights into the function, such as finding concavity and inflection points.
- In our exercise, calculating successive derivatives of the function \[ f(x)=\frac{1}{(x-1)^2} \] was pivotal in forming the Maclaurin series. Each derivative gives us additional terms of increasing degree in the polynomial approximation.
remainder term
When we expand a function into a Taylor or Maclaurin series, the series is often truncated after a finite number of terms, forming a polynomial approximation. However, there is always some error or 'remainder' left, known as the remainder term.
- The remainder term quantifies the difference between the actual function and its polynomial approximation.
- Mathematically, for a Taylor series approximation up to the nth degree, the remainder term \(R_n(x)\) is given by:\[R_n(x) = \frac{f^{(n+1)}(c)(x-a)^{n+1}}{(n+1)!}\]
- Here, 'c' is some value between 'a' and 'x'.