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
Applied Optimization
Problem 49b
Textbook Question
Travel costs A simple model for travel costs involves the cost of gasoline and the cost of a driver. Specifically, assume gasoline costs $p/gallon and the vehicle gets g miles per gallon. Also assume the driver earns $w/hour.
b. At what speed does the gas mileage function have its maximum?

1
To find the speed at which the gas mileage function has its maximum, we need to understand the relationship between speed and gas mileage. Typically, gas mileage (miles per gallon) is a function of speed, and it can be represented as a function f(v), where v is the speed of the vehicle.
The maximum gas mileage occurs at the speed where the derivative of the gas mileage function with respect to speed is zero. This is because the derivative represents the rate of change, and a zero derivative indicates a local maximum or minimum.
First, express the gas mileage function f(v) in terms of speed v. This function is often derived from empirical data or a model that relates speed to fuel efficiency.
Next, find the derivative of the gas mileage function, f'(v), with respect to speed v. This involves applying differentiation rules to the function f(v).
Finally, solve the equation f'(v) = 0 to find the critical points. Evaluate these points to determine which one corresponds to the maximum gas mileage. This involves checking the second derivative or analyzing the behavior of the function around the critical points.

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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Gas Mileage Function
The gas mileage function describes how the fuel efficiency of a vehicle varies with speed. Typically, this function increases to a certain point (optimal speed) and then decreases as speed continues to rise. Understanding this function is crucial for determining the speed at which gas mileage is maximized, which directly impacts travel costs.
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Optimization
Optimization in calculus involves finding the maximum or minimum values of a function. In this context, we need to apply techniques such as taking the derivative of the gas mileage function and setting it to zero to find critical points. This process helps identify the speed that minimizes fuel costs by maximizing gas mileage.
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Derivatives
Derivatives represent the rate of change of a function with respect to a variable. In this scenario, the derivative of the gas mileage function will indicate how mileage changes as speed varies. By analyzing the derivative, we can determine where the function reaches its maximum value, which is essential for solving the problem.
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