November 19, 2012Graphing Linear Equations using a table and x-

and y-intercepts

Warm-up: For #1-3, use the relation, {(3, 2), (-2, 4), (4, 1), (-1, 2), (0, 5)1. Identify the domain and range.2. Is the relation a function? Explain.3. What is the inverse of the relation?4. If f(x) = 3x – 5, find f(-2)

HW 4.5: Pg. 221 #16-24even, graph 27-33 odd using a table, 35 and 37 using x- and y-intercepts

Lesson 5.4 Linear Equations- Look only at the equations: How do you know when it is linear and when it is not?- Come up with some general rules for determining linear function equations.

y

x5

5

-5

-5

5x + y = 1

y

x5

5

-5

-5

p(x) = 3x2 – 4

y

x5

5

-5

-5

x

xxg

7

)(y

x5

5

-5

-5

5

12)(

x

xh

y

x5

5

-5

-5

13

2)( xxf

y

x5

5

-5

-5

2 xy

Identifying Linear Functions

What makes something linear?– X with nothing extra - no exponents, no square roots,

not in a denominator– The graph is a line!

• Examples: Are these linear functions?

Graphing an Equation using a table.Any equation can be graphed using a table!Graph y = 4 – 3x

x y = 4 – 3x y (x,y)

What is the Domain and Range?

Let’s Graph!

If you continued to find more points, you would notice that it starts to form a line on the graph that goes forever!

Therefore, y = 4 – 3x , is called a Linear Equation

Standard Form• Ax + By = C– A, B, and C are integers– A is positive– A and B are not both zero

• Identify A, B, and C:3x – 5y = 12

Example 1: Rewrite the linear equation in Standard Form: 2y – 4x + 10 = 11

Using the x- and y-intercepts when a linear equation is in Standard Form

What are x and y intercepts? Where are they on a graph?

x-intercept – where the graph crosses the x-axis

y-intercept – where the graph crosses the y-axis

Finding the x- and y-intercepts and graph 3x – 2y = 15

X - intercept: (x, 0)y = 0, so plug in 0 for y and

solve for x.

Y - intercept: (0, y)x = 0, so plug in 0 for x and solve for y.