1. 2-2 Linear Equations
Objective: To identify equations that are linear and graph them, to write linear equations in standard form, and to determine the x- and y- intercepts of a line and use them to graph an equation.
HW 2-2, pg 77, #18-36 (all)
Copy problems, show work.
HEADING, TITLE, OBJECTIVE!

2. Drill #18*
Write each equation in Standard Form where A, B, and C are integers whose greatest common factor is 1. Identify A, B, and C.
1. y = -8x + 6
2. ¼ x = ½ y + 5
3. 3x – 12y = 15.

3. Linear Functions A function is linear if it can be defined by
f(x) = mx + b, where m and b are real numbers.
What is the difference between this form and standard form?
What happens when the slope is 0?

4. Classwork #18* Identify whether the following functions are linear:
4. f(x) = 4x + 5
5. g(x) = 6 – ½ x
6. h(x) =
7. p(x) = 6

5. Constant Functions ** (17.)
Constant Function: A function whose value does not change. (all constant functions are horizontal lines with a slope of 0)
f(x) = 0 is called the zero function.
What else is this line known as?

6. Classwork #18* Graph the following constant functions: 8. f(x) = 0
9. g(x) = -2

7. x and y intercepts **
18. x – intercept: the x-coordinate of the point where the graph of a function crosses the x-axis.
NOTE: At the x – intercept (on the x – axis), y = 0
19. y – intercept: the y-coordinate of the point where the graph of a function crosses the y-axis.
NOTE: At the y – intercept (on the y – axis), x = 0

8. Finding the x- and y- intercepts
You can easily graph equations by using the x- and y- intercepts.
Steps:
To find the x- intercept, substitute y = 0 into the equation, and solve for x
To find the x- intercept, substitute y = 0 into the equation, and solve for x.
Plot both points and connect. (remember to label your axes, and put arrowheads on your line.)

9. Example Graph 5x – 3y = 15 using x – and y – intercepts. Classwork:
Graph the following:
10. x + 2y = 4
11. 2x – 3y = 6

10. Example 4
Page 75, Example 4.