MTH 100
Graphs Of Linear Functions
Objectives
1. Graph Linear Functions by Plotting Points.
2. Graph Linear Functions by Using Intercepts.
3. Graph Horizontal and Vertical Lines.
Overview
• Recall, from Section 2.1, that a linear equation
can be represented by a straight line.
• A linear function can also be represented by a
straight line.
• IMPORTANT: “f(x)” means the same thing as
“y”.
Objective 1
• The table-of-values method will work here just
as it did previously.
• If the function is written as “f(x) =“, or “y = “,
choose values for x only.
• Examples: f ( x)  3 x  2
3
y  x2
5
 2 x  5 y  14
Objective 2
• Recall, from Section 2.1, that:
--to find an x-intercept, set y = 0 and solve for x;
--to find a y-intercept, set x = 0 and solve for y
(remember, f(x) means the same as y).
• Examples: 4 x  5 y  20
1
f ( x)  x  1
3
y  2x
Objective 3
• A linear equation written “x =“ produces a
vertical line.
• A linear equation written “y =“ or “f(x) =“
produces a horizontal line.
• Examples: x  5
y  1
f ( x)  4