1. 3.2 Linear Functions

2. What We Will Learn
Identify linear functions using graphs, tables, and equations
Graphing using discrete or continuous data

3. Needed Vocab
Linear equation in two variables: equation using two variables like y = mx+ b
Linear function: function whose graph is a nonvertical line with a constant rate of change
Nonlinear function: does not have a constant rate of change
Solution of equation in two variables: ordered pair (x,y) that makes the equation true
Discrete domain: set of input values that consists of only certain numbers in an interval
Continuous domain: set of input values that consists of all numbers in an interval

4. Ex. 1 Is It Linear or Nonlinear
Y - axis
X - axis

5. Ex. 2 Is It Linear or Nonlinear
See how numbers go up or down starting with the first
if by same amount on top and same amount on bottom, then linear
Linear
nonlinear +3 +3 +3 +2 +2 +2 X 3 6 9 12 Y 36 30 24 18 x 1 3 5 7 y 2 9 20 35 +7
+11
+15 -6 -6 -6

6. Your Practice
nonlinear +1 +1 +1 x 1 2 3 4 y 16 8 -8 -4 -2

7. Exs. 4 and 5 Discrete or Continuous Domains
The function 𝑦=15.95𝑥 represents the cost of buying concert tickets. You can buy a maximum of 4 tickets. Is the domain discrete or continuous? What is the domain? Graph using the domain.
Discrete or Continuous?
Discrete
Cannot buy half a ticket
Domain?
0 𝑡𝑜 4
Cannot buy more than 4
Graph
Do not connect dots because discrete