Table of contents
- 0. Functions7h 52m
- Introduction to Functions16m
- Piecewise Functions10m
- Properties of Functions9m
- Common Functions1h 8m
- Transformations5m
- Combining Functions27m
- Exponent rules32m
- Exponential Functions28m
- Logarithmic Functions24m
- Properties of Logarithms34m
- Exponential & Logarithmic Equations35m
- Introduction to Trigonometric Functions38m
- Graphs of Trigonometric Functions44m
- Trigonometric Identities47m
- Inverse Trigonometric Functions48m
- 1. Limits and Continuity2h 2m
- 2. Intro to Derivatives1h 33m
- 3. Techniques of Differentiation3h 18m
- 4. Applications of Derivatives2h 38m
- 5. Graphical Applications of Derivatives6h 2m
- 6. Derivatives of Inverse, Exponential, & Logarithmic Functions2h 37m
- 7. Antiderivatives & Indefinite Integrals1h 26m
- 8. Definite Integrals3h 25m
4. Applications of Derivatives
Differentials
Problem 4.8.39
Textbook Question
{Use of Tech} Estimating roots The values of various roots can be approximated using Newton’s method. For example, to approximate the value of ³√10, we let x = ³√10 and cube both sides of the equation to obtain x³ = 10, or x³ - 10 = 0. Therefore, ³√10 is a root of p(x) = x³ - 10, which we can approximate by applying Newton’s method. Approximate each value of r by first finding a polynomial with integer coefficients that has a root r. Use an appropriate value of x₀ and stop calculating approximations when two successive approximations agree to five digits to the right of the decimal point after rounding.
r = 7¹/⁴
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1
Identify the polynomial that has the root r = 7^(1/4). This can be expressed as p(x) = x^4 - 7, since 7^(1/4) is a root of this polynomial.
Choose an initial guess x₀ for the root. A reasonable starting point could be x₀ = 2, since 2^4 = 16 is greater than 7, and 1 is less than 7.
Apply Newton's method using the formula x_{n+1} = x_n - rac{p(x_n)}{p'(x_n)}, where p'(x) is the derivative of p(x). Calculate p'(x) = 4x^3.
Calculate the first iteration using your initial guess x₀. Substitute x₀ into the formula to find x₁, and then repeat this process to find x₂.
Continue iterating until the difference between two successive approximations is less than 0.00001, ensuring that they agree to five decimal places.
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