Chapter 2 Section 2 Linear Equations Pt 1 Algebra 2 Notes January 12, 2009

Warm-Ups Find the domain and range of each relation and determine whether it is a function: {(2, 4), (4, 8), (8, 16)} {(-1, 2), (-2, 5), (-2, 7), (0, 2), (9, 2)} Evaluate the following expression for x = -2 Evaluate the following expression for x = 4

Linear Functions Linear Function: A function who’s graph is a line. A linear function can be expressed, or represented, by a Linear Equation. For Example: The linear equation y = 3x + 2 represents this linear function

Graphing Linear Equations Choose two values for x and find the corresponding values for y Plot the point for each ordered pair Complete the graph by drawing a line through the points Make A Table:

Give it a try… Graph the following equations in your notes: What is the y-intercept of each graph? What is the x-intercept of each graph?

Forms of Lines Standard Form: You can graph a linear equation in standard form by finding the x- and y-intercepts Example: Graph the following equation

Forms of Lines cont. Slope-Intercept Form: m represent the slope of the line b represents the y-intercept of the line

Forms of Lines cont. Point-Slope Form: represents a point on the line m represents the slope of the line

Slope of a Line What does “slope” mean to you???

Finding the Slope of a Line Slope: the ratio of the vertical change (change in y) over the horizontal change (change in x) Given two points on a line: Use the equation for slope to find the slope of that line:

Finding the Slope of a Line Find the slope of the line that goes through the points:

Try One On Your Own: Find the slope of each line that goes through the points: a) b)

Finding Slope with Slope-Intercept Form What is the slope in this equation? Convert the following equations into slope-intercept form and then determine the slope of the line:

Homework #4 Pg 67 #3, 6, 8, 11-13, 17- 19, 32, 36