Graphing Linear Equations Essential Question: How do you graph linear equations using point plotting, intercepts, the slope- intercept form, and the graphing calculator?

Graphing Linear Equations Using Point Plotting

In order to graph using point plotting, you will need to create a table. You will need to choose at least 3 numbers for x and “plug” them into the equation to find corresponding y values. Plot the points For Example: Graph y = 2x - 1 x y Choose x values -1 2(-1)-1=-3 2(0)-1 = -1 1 2(1)-1 = 1 “plug” x into the equation

Graph using point plotting x y (-2) + 3 = 2 -2 2 (0) + 3 = 3 (2) + 3 = 4

Graphing Using Intercepts

To graph using intercepts, you will need to find both the X and the y intercept To find the x-intercept, substitute “0” for y and solve for x To find the y – intercept, substitute “0” for x and solve for y For example: y = 4x + 8 X-intercept: 0 = 4x + 8 -8 = 4x -2 = x Y – Intercept: Y = 4(0) + 8 Y = 8

Graph 2x + 3y = 6 using intercepts. X-intercept: 2x + 3(0) = 6 2x = 6 X = 3 Y-intercept: 2(0) + 3y = 6 3y = 6 Y = 2

Graphing Using the Slope-Intercept Form

To graph a linear equation, you will need to find the slope and the y-intercept for the equation. Remember: y = mx + b slope Y-intercept (the point where the graph crosses the y-axis)

Slope = Y-intercept = Graph 1. Plot the y-intercept Use the slope to find the next point Slope = “rise over run”

Graph 2x + 5y = 10 using the slope-intercept form: (put the equation in slope-intercept form first) 2x + 5y = 10 5y = 10 – 2x y = 2 – 2/5 x slope = -2/5 y – intercept = 2 A negative slope means you will go down then right from the y-intercept

Graphing Using the Graphing Calculator

Use the link below to access an online graphing calculator: http://www.coolmath.com/graphit/index.html When using the calculator, you will first need to have the equation in slope-intercept form (y = mx + b) Then simply key in the equation and hit EVAL to see the graph Graph on the graphing calculator

Graph 3x – 5y = 9 on the graphing calculator. (First you will need to solve for y). 3x – 5y = 9 -5y = 9 – 3x Put the above equation into the graphing calculator and click EVAL

Assignment and Review Use the word document link below to access a homework assignment. Homework Use the internet link below to access a game you can use to review graphing linear equations. http://funbasedlearning.com/algebra/graphing/lines/default.htm

Use the link below to access a Lesson Quiz. Good Luck!! Be sure to submit all your work to your teacher when completed!