Topic: Functions and Graphs I
Subtopic: Functions II - Domain, Range, and Operations
Overview
We recently introduced functions and function notation. Today we delve deeper into the graphs of functions by studying the domain and range of a function. We learn to perform algebraic operations on functions such as multiplying two functions together to form a new function.
Objectives
By the end of this topic you should know and be prepared to be tested on:
- 3.4.1 Find domain and range given: set of ordered pairs, mapping, graph, or equation
- 3.4.2 Perform operations on function (e.g., add, subtract, multiply by a number, find the product or quotient of two functions)
- 3.4.3 Find domain restrictions (if any) of a "combination" function such as fg or f/g
Terminology
Define: domain, range, product, quotient, combination function
Text Notes
Text:
Intro & Inter Algebra for CS 3ed by Blitzer, sect. 8.2-8.3
- ch 8.1-8.3 Caution: The text covers foil before functions, but the Clark elementary algebra curriculum covers functions first. So we jumped ahead to chapter 8 to pick up functions but the text includes foil in some of the exercises. THERE WILL BE NO FOIL PROBLEMS ON THIS WEEK'S QUIZ! We'll leave those until after we cover foil later in the course. So there will be NO problems such as simplify a function that has a binomial times a binomial like (x+2)(x-1) because to do that multiplication involves foil. You can SKIP any exercises that involve multiplying a binomial times a binomial.
- ch 8.2 focuses on finding domains and ranges of functions/graphs and writing those sets in interval notation.
- ch 8.3 pg 576 summarizes the four basic ways of algebraically combining functions. Pay attention to the notation. Example 4 provides a good overview of the processes.
- ch 8.3 Knowing how to find the domain of a single given function (e.g., example 1 pg 575) is important. But finding the domain of a combined function (e.g., example 3b pg 377) is optional.
- ch 8.3 skip example 5 and similar application problems in this section. These are covered in a 100-level math course.