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 Integrals4h 44m
- 9. Graphical Applications of Integrals2h 27m
- 10. Physics Applications of Integrals 2h 22m
5. Graphical Applications of Derivatives
Intro to Extrema
Problem 4.1.33
Textbook Question
Locating critical points Find the critical points of the following functions. Assume a is a nonzero constant.
ƒ(x) = eˣ + e⁻ˣ

1
To find the critical points of the function \( f(x) = e^x + e^{-x} \), we first need to find its derivative. The derivative of \( e^x \) is \( e^x \), and the derivative of \( e^{-x} \) is \( -e^{-x} \). Therefore, the derivative \( f'(x) \) is \( e^x - e^{-x} \).
Set the derivative equal to zero to find the critical points: \( e^x - e^{-x} = 0 \).
To solve \( e^x - e^{-x} = 0 \), add \( e^{-x} \) to both sides to get \( e^x = e^{-x} \).
Recognize that \( e^x = e^{-x} \) implies \( e^{2x} = 1 \) by multiplying both sides by \( e^x \).
Solve \( e^{2x} = 1 \) by taking the natural logarithm of both sides, which gives \( 2x = 0 \). Therefore, \( x = 0 \) is the critical point.

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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Critical Points
Critical points of a function occur where its derivative is either zero or undefined. These points are essential for identifying local maxima, minima, and points of inflection. To find critical points, one must first compute the derivative of the function and then solve for the values of x that satisfy the condition of the derivative being zero.
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Derivative
The derivative of a function measures the rate at which the function's value changes as its input changes. It is a fundamental concept in calculus that provides information about the function's slope at any given point. For the function ƒ(x) = eˣ + e⁻ˣ, the derivative can be calculated using the rules of differentiation, particularly the exponential function's properties.
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Exponential Functions
Exponential functions are mathematical functions of the form f(x) = a^x, where 'a' is a constant and 'x' is the variable. They are characterized by their rapid growth or decay and are crucial in various applications, including modeling population growth and radioactive decay. In the given function, eˣ and e⁻ˣ are examples of exponential functions, which will influence the behavior of the derivative and the location of critical points.
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