Skip to main content
Ch. 4 - Applications of the Derivative
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Non è quello che usi tu?Cambia libro di testo
Capitolo 4, Problema 4.8.5

Let ƒ(x) = 2x³ - 6x² + 4x. Use Newton’s method to find x₁ given that x₀ = 1.4. Use the graph of f (see figure) and an appropriate tangent line to illustrate how x₁ is obtained from x₀ . <IMAGE>

Guida verificata passo dopo passo
1
Newton's method is an iterative process used to approximate the roots of a real-valued function. The formula for Newton's method is: x_{n+1} = x_n - \(\frac{f(x_n)}{f'(x_n)}\).
First, we need to find the derivative of the function f(x) = 2x^3 - 6x^2 + 4x. The derivative, f'(x), is calculated as follows: f'(x) = \(\frac{d}{dx}\)(2x^3 - 6x^2 + 4x) = 6x^2 - 12x + 4.
Next, substitute x_0 = 1.4 into the function f(x) and its derivative f'(x) to find f(1.4) and f'(1.4).
Calculate f(1.4) = 2(1.4)^3 - 6(1.4)^2 + 4(1.4) and f'(1.4) = 6(1.4)^2 - 12(1.4) + 4.
Finally, use the Newton's method formula to find x_1: x_1 = 1.4 - \(\frac{f(1.4)}{f'(1.4)}\). This will give you the next approximation of the root, x_1.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
1m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Newton's Method

Newton's Method is an iterative numerical technique used to approximate the roots of a real-valued function. It starts with an initial guess and uses the function's derivative to find successively better approximations. The formula for updating the guess is x₁ = x₀ - f(x₀)/f'(x₀), where f' is the derivative of f. This method is particularly effective when the initial guess is close to the actual root.
Video consigliato:
Percorso guidato
4:26
Evaluating Composed Functions

Derivative

The derivative of a function measures how the function's output changes as its input changes. It is defined as the limit of the average rate of change of the function as the interval approaches zero. In the context of Newton's Method, the derivative is crucial for determining the slope of the tangent line at the current guess, which guides the next approximation towards the root.
Video consigliato:

Tangent Line

A tangent line to a curve at a given point is a straight line that touches the curve at that point and has the same slope as the curve at that point. In Newton's Method, the tangent line at the point (x₀, f(x₀)) is used to find the next approximation x₁. The intersection of this tangent line with the x-axis provides a new estimate for the root, illustrating how the method converges to the actual solution.
Video consigliato:
Percorso guidato
05:13
Slopes of Tangent Lines