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 4.8.49
Textbook Question
{Use of Tech} Fixed points An important question about many functions concerns the existence and location of fixed points. A fixed point of f is a value of x that satisfies the equation f(x) = x; it corresponds to a point at which the graph of f intersects the line y = x. Find all the fixed points of the following functions. Use preliminary analysis and graphing to determine good initial approximations.
f(x) = cos x

1
Understand the definition of a fixed point: A fixed point of a function f(x) is a value x such that f(x) = x. For the function f(x) = \cos(x), we need to find x such that \cos(x) = x.
Perform a preliminary analysis: Consider the range of the cosine function, which is [-1, 1]. This means any fixed point must lie within this interval.
Graph the functions y = \cos(x) and y = x: By graphing these two functions, you can visually identify where they intersect. These intersection points are the fixed points.
Use numerical methods for better approximation: Since \cos(x) is a transcendental function, finding an exact solution algebraically might be challenging. Use numerical methods like the Newton-Raphson method or fixed-point iteration to approximate the solution.
Verify the solution: Once you have an approximate solution, substitute it back into the equation \cos(x) = x to check if it holds true within an acceptable margin of error.
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