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
5. Graphical Applications of Derivatives
Finding Global Extrema
Problem 4.1.51
Textbook Question
Absolute maxima and minima Determine the location and value of the absolute extreme values of ƒ on the given interval, if they exist.
ƒ(x) = sin 3x on [-π/4,π/3]

1
First, identify the critical points of the function ƒ(x) = sin(3x) within the interval [-π/4, π/3]. To do this, find the derivative of ƒ(x), which is ƒ'(x) = 3cos(3x).
Set the derivative ƒ'(x) = 3cos(3x) equal to zero to find the critical points: 3cos(3x) = 0. Solve for x to find the critical points within the interval.
Evaluate the function ƒ(x) = sin(3x) at the critical points found in the previous step, as well as at the endpoints of the interval, x = -π/4 and x = π/3.
Compare the values of ƒ(x) at the critical points and the endpoints to determine which is the absolute maximum and which is the absolute minimum.
Conclude by stating the location and value of the absolute maximum and minimum of ƒ(x) on the interval [-π/4, π/3].

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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Absolute Extrema
Absolute extrema refer to the highest and lowest values of a function over a specified interval. To find these values, one must evaluate the function at critical points, where the derivative is zero or undefined, as well as at the endpoints of the interval. The largest of these values is the absolute maximum, while the smallest is the absolute minimum.
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Critical Points
Critical points are values of the independent variable where the derivative of the function is either zero or does not exist. These points are essential in determining the behavior of the function, as they can indicate potential locations for local maxima or minima. To find critical points, one must first compute the derivative of the function and solve for when it equals zero or is undefined.
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Evaluating Functions on an Interval
Evaluating a function on a closed interval involves checking the function's values at both endpoints and at any critical points found within the interval. This process ensures that all potential candidates for absolute extrema are considered. The function's behavior can vary significantly across the interval, making this evaluation crucial for accurately identifying absolute maximum and minimum values.
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