2: Functions
- Page ID
- 26491
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- A jetliner changes altitude as its distance from the starting point of a flight increases. The weight of a growing child increases with time. In each case, one quantity depends on another. There is a relationship between the two quantities that we can describe, analyze, and use to make predictions. In this section, we will analyze such relationships.
- 2.2: Domain and Range
- In creating various functions using the data, we can identify different independent and dependent variables, and we can analyze the data and the functions to determine the domain and range. In this section, we will investigate methods for determining the domain and range of functions.
- 2.3: Piecewise-Defined Functions
- In preparation for the definition of the absolute value function, it is extremely important to have a good grasp of the concept of a piecewise-defined function.
- 2.4: Absolute Value
- The absolute value of a number is a measure of its magnitude, sans (without) its sign.
- 2.6: Break-Even Analysis (Sink or Swim)
- Simply looking at the fixed costs, variable costs, potential revenues, contribution margins, and typical net income is not enough. Ultimately, all costs in a business need to be recovered through sales. Do you know how many units have to be sold to pay your bills? The answer to this question helps assess the feasibility of your business idea.
- 2.7: Applications
- Now that we have learned to determine equations of lines, we get to apply these ideas in a variety of real-life situations.
- 2.9: Quadratic Functions
- In this section, we will explore the family of 2nd degree polynomials, the quadratic functions. While they share many characteristics of polynomials in general, the calculations involved in working with quadratics is typically a little simpler, which makes them a good place to start our exploration of short run behavior.
- 2.10: Power Functions and Polynomial Functions
- Suppose a certain species of bird thrives on a small island. The population can be estimated using a polynomial function. We can use this model to estimate the maximum bird population and when it will occur. We can also use this model to predict when the bird population will disappear from the island. In this section, we will examine functions that we can use to estimate and predict these types of changes.
- 2.11: Graphs of Polynomial Functions
- The revenue in millions of dollars for a fictional cable company can be modeled by the polynomial function From the model one may be interested in which intervals the revenue for the company increase or decreases? These questions, along with many others, can be answered by examining the graph of the polynomial function. We have already explored the local behavior of quadratics, a special case of polynomials. In this section we will explore the local behavior of polynomials in general.
- 2.12: Graphing Rational Functions
- We’ve seen that the denominator of a rational function is never allowed to equal zero; division by zero is not defined. So, with rational functions, there are special values of the independent variable that are of particular importance. Now, it comes as no surprise that near values that make the denominator zero, rational functions exhibit special behavior, but here, we will also see that values that make the numerator zero sometimes create additional special behavior in rational functions.