SWBAT… graph linear equations using a table of values Tuesday, 11/30/10 SWBAT… graph linear equations using a table of values Agenda WU (10 min) Notes on linear equations w/ two practice problems (30 min) Warm-Up Using a red pen, correct the equations test problems you got wrong. Do the corrections on your test (no need to explain) Set up your Cornell Notes. Topic is Graphing Linear Equations Cut a piece of graph paper into 4 squares. HW#2: Graphing Linear Equations

Equations Test Answers x = 36 No Solution x = 12 x = 305 Infinite Solution a = 8 x = (y – b)/m b = 3 a = 11/(q – 3) (divide both sides by q – 3)

Graphing Linear Equations Infinity HS Ms. Sophia Papaefthimiou

Graphing linear equations To graph a linear equation you can use: 1.) Table of values (today’s lesson) 2.) Intercepts (next project) 3.) Slope intercept form (y = mx + b) (next project)

What is a Linear Equation? A linear equation is an equation whose graph is a LINE. y x Using a graph paper square sketch a line with a negative slope. Linear Not Linear

What is a Linear Equation? y x The equations we will be graphing have two variables, x and y. For example, A solution to the equation is any ordered pair (x , y) that makes the equation true. The ordered pair (3 , 2) is a solution since, If we were to plot all these ordered pairs on a graph, we would be graphing a line.

Ex 1: Graph y = 3x – 2 using a Table of Values Step 1: Solve for y

Ex 1: Graph y = 3x – 2 using a Table of Values Step 2: Make a table of values x 3x – 2 y (x, y)

The x - values are picked by YOU! Ex 1: Graph y = 3x – 2 using a Table of Values x 3x – 2 y (x, y) –2 –1 1 2 The x - values are picked by YOU!

Ex 1: Graph y = 3x – 2 using a Table of Values (x, y) -2 3(-2) – 2 -8 (-2, -8) -1 1 2

Ex 1: Graph y = 3x – 2 using a Table of Values (x, y) -2 3(-2) – 2 -8 (-2, -8) -1 3(-1) – 2 -5 (-1, -5) 3(0) – 2 (0, -2) 1 3(1) – 2 (1, 1) 2 3(2) – 2 4 (2, 4)

Ex 1: Graph y = 3x – 2 using a Table of Values

-1/2x + y = -3 (Add 1/2x from both sides) Ex 2: Graph -1/2x + y = -3 using a table of values Step 1: Solve for y: -1/2x + y = -3 (Add 1/2x from both sides) y = 1/2x – 3

Ex 2: Graph -1/2x + y = -3 using a table of values Step 2: Make a Table of Values x 1/2x – 3 y (x, y) –2 –1 1 2

Ex 1: Graph -1/2x + y = -3 using a Table of Values http://www. glencoe

Ex. 3: Graph x – 2y = 5 First Step: Solve for y (write y as a function of x) x – 2y = 5 –2y = -x + 5

Second Step: Make a Table of Values x y (x, y) -2 -3.5 (-2, -3.5) -1 (-1, -3) -2.5 (0, -2.5) 1 (1, -2) 2 -1.5 (2, -1.5)

Graphing Horizontal & Vertical Lines y x When you are asked to graph a line, and there is only ONE variable in the equation, the line will either be vertical or horizontal. Graph x = 3 Since there are no y–values in this equation, x is always 3 and y can be any other real number. y = –2 Graph y = –2 Since there are no x–values in this equation, y is always –2 and x can be any other real number. x = 3

SWBAT… learn about high school credits, required classes, and credits Thurs, 12/2/10 Agenda Quiz (5 min) Guest speaker: Ms. Leary (40 min) Warm Up QUIZ: On graph paper: 1.) Graph 3x + y = 4 (Hint: solve for y first) 2.) Graph x = -6 3.) Graph y = 1 HW#2: Graphing Linear Equations (both sides)

y x Graph x = -6 Since there are no y–values in this equation, x is always -6 and y can be any other real number. y = 1 Graph y = 1 Since there are no x–values in this equation, y is always 1 and x can be any other real number. x = -6