2.3

2.3 LINEAR FUNCTIONS AND SLOPE-INTERCEPT FORM

SLOPE

TYPES OF SLOPE

EXAMPLE: WHAT IS THE SLOPE OF THE LINE THAT PASSES THROUGH THE TWO POINTS?

3,7 & 2,4

3,1 & 4,1

7, 3 & 7,1

LINEAR FUNCTIONS

A linear function is a function whose graph is a line.

We represent a linear function with a linear equation.

INTERCEPTS

An intercept of a line is a point where a line crosses an axis. The y-intercept of a nonvertical line is the point

at which the line crosses that y-axis. The x-intercept of a nonhorizontal line is the

point at which the line crosses the x-axis.

SLOPE – INTERCEPT FORM

EXAMPLE: WHAT IS AN EQUATION OF THE LINE

and the y-intercept is 1

5m 0, 3

EXAMPLE: WHAT IS AN EQUATION OF THE LINE

WORKING WITH LINEAR EQUATIONS

We can rewrite a linear equation in slope – intercept form by solving for y.

EXAMPLE: WRITE THE EQUATION IN SLOPE – INTERCEPT FORM. WHAT ARE THE SLOPE AND Y-INTERCEPT.

5 4 16x y

EXAMPLE: WRITE THE EQUATION IN SLOPE – INTERCEPT FORM. WHAT ARE THE SLOPE AND Y-INTERCEPT.

3 11

4 2x y

GRAPHING A LINEAR EQUATION

1. Given an equation of a line, write the equation in slope-intercept form

2. Plot the y-intercept3. Use the slope to find a second point4. Sketch the line

EXAMPLE: GRAPH THE LINE

2 1x y

EXAMPLE: GRAPH THE LINE

4 7 14x y

ASSIGNMENT

Page 78 #9 – 35 odd, 18, 47, 48, 51 – 55 odd, 59, 61