Relations and Functions Lesson 4: Properties of Linear Relations
Todays Objectives Graph a set of data and determine the restrictions on the domain and range Sort a set of graphs as functions and non-functions
Properties of Linear Relations Before we start, work with a partner to complete A - C in the Try This activity on page 301. You can use the grid paper on your handout.
Solutions Width (units) Area (cm 2 ) Width (units) Perimeter (units) Non-linear (points not a straight line ) Linear (points in a straight line) Linear : means a graph has points that connect in a straight line or a graph is a straight line
Linear Relations The cost for a car rental is $60, plus $20 for every 100 km driven. The independent variable is the distance driven and the dependent variable is the cost. There are many different ways that we can identify that this is a linear relation: Table of values Set of ordered pairs Graph
Identifying Linear Relations: Table of Values Distance (km)Cost ($) Constant difference in independent and dependent variable = linear relation For a linear relation, a constant change in the independent variable results in a constant change in the dependent variable.
Identifying Linear Relations: Set of Ordered Pairs
Identifying Linear Relations: Graph Car Rental Cost Cost ($) Distance (km)
Rate of Change The rate of change is $0.20/km ; that is, for each additional 1 km driven, the rental cost will increase by 20 cents. The rate of change is constant for a linear relation. In any equation of the form y = mx + b, we can determine the rate of change by looking at the value of m. For example, an equation for this relation could be C = 0.20d + 60, where: C is the dependent variable, cost d is the independent variable, distance, 60 is the initial amount, and 0.20 is the rate of change (slope)
Example (You do) Graph each equation and state whether or not it is linear A) y = -3x + 25 B) y = 2x xy xy
Solutions AB LinearNon-linear
Example A water tank on a farm holds 6000 L. Graph A represents the tank being filled at a constant rate. Graph B represents the tank being emptied at a constant rate. Graph A: Filling the tank Volume (L) Time (min) a)What is the independent /dependent variable? b)What is the rate of change?
Example
Example: You do a)What is the independent /dependent variable? b)What is the rate of change? Volume (L) Time (min) Graph B: Emptying the Tank
Example
Homework Pg #3,5,7,9,11,13,15,17,19,22 Chapter 5 Vocab Quiz – Next Wednesday (may include any words from handouts) Provincial Exam Practice – Next Friday Chapter 5 Test – Tuesday, March 19
Wall Quiz In teams of 3, move around the classroom and answer the questions posted on the walls After the time runs out, return to your seats and we will compare answers The team(s) with the most correct answers will win candy!