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
Intro to Extrema
Problem 4.1.89b
Textbook Question
Values of related functions Suppose f is differentiable on (-∞,∞) and assume it has a local extreme value at the point x = 2, where f(2) = 0. Let g(x) = xf(x) + 1 and let h(x) = xf(x) + x +1, for all values of x.
b. Does either g or h have a local extreme value at x = 2? Explain.
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1
Since f has a local extreme value at x = 2, we know that f'(2) = 0. This is a key point to analyze the functions g and h.
To determine if g has a local extreme value at x = 2, we need to compute g'(x) using the product rule: g'(x) = f(x) + x f'(x).
Evaluate g'(2) by substituting x = 2 into the derivative: g'(2) = f(2) + 2 f'(2). Since f(2) = 0 and f'(2) = 0, we find that g'(2) = 0.
Next, we check if h has a local extreme value at x = 2 by computing h'(x): h'(x) = f(x) + x f'(x) + 1.
Evaluate h'(2) by substituting x = 2 into the derivative: h'(2) = f(2) + 2 f'(2) + 1. Since f(2) = 0 and f'(2) = 0, we find that h'(2) = 1.
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