SWBAT… Write lines in slope-intercept form Tues, 1/19/10 Agenda 1.WU (5 min) 2.Graphing Calculator Activity (30 min) 3.Discussion (15 min) 4.Exit slip.

SWBAT… Write lines in slope-intercept form Tues, 1/19/10

Agenda1. WU (5 min)2. Graphing Calculator Activity (30 min)3. Discussion (15 min)4. Exit slip (5 min)

WU: Make the below corrections to the study guide:

#30: B. (7/4, 0), (0, -7/5)

#35: Change question: y = 3x + 2

Complete Study Guide!

• #2A) What conclusion can you make about the y-intercept (b) and and where it crosses the y-axis?

• What ever the value of b is, that is where the line will cross the y-axis.

• #2B) How did the graph of y = x + 1 transform from the parent function y =x?

• The line shifted up one unit.

What insight did you gain from this graphing calculator activity

(4th period)1. That you can graph a line on a calculator

and the calculator shows you the line2. The m is always in front of the x3. Step 1: First you plot the y-intercept (b)4. Step 2: Then you plot m from where you

left off5. The y-intercept (b) is where b crosses

the y-axis


(2nd period)1. How to use a graphing calculator2. Y = mx + b, m is the number in front of

x3. b is called the y-intercept4. Step 1: You use b to plot your first

point5. Step 2: You then plot the slope from

the y-intercept


(6th period)1. Given y = mx + b, m is the number in

front of x2. Calculators can graph lines3. b is the y-intercept4. Step 1: First you plot the y-intercept onto

the graph5. Step 2: You then plot the slope from

where you left off

SWBAT… Write lines in slope-intercept form Wed, 1/20/10

Agenda1. Warm-up (5 min)2. Notes on slope intercept – 5 examples (25 min)3. Work on hw#3 (15 min)

WARM-UPWhat is the slope and y-intercept of each

equation:

1. y = 4x + 22. y = -x – 23. y = 3x 4. y = -5

HW#3: Writing equations in slope-intercept form and COMPLETE STUDY GUIDE!!

Conclusion “I” from TI-83 Activity:

• Graph #4 rises and graph #9 falls. This is because the slope of #4 is positive and the slope of #9 is negative.

• The graph of #4 crosses on the negative side of the y-axis and the graph of #9 crosses on the positive side of the y-axis. This is because #4 has a y-intercept of -2 and #9 has a y-intercept of 1.

Slope-intercept form:Slope-intercept form:Slope-intercept form:Slope-intercept form:

What is the slope? ____________

2 1y x Now look at the equation below……

What is the y-intercept? ____________

Given y = 4x + 2, what is the slope and the y-intercept?m = 4b = 2

Given y = -x – 2, what is the slope and the y-intercept?

m = -1b = -2

Given y = 3x, what is the slope and the y-intercept?

m = 3b = 0

Given y = -5, what is the slope and the y-intercept?

m = 0b = -5

• y = mx+ b is an equation that defines a line

• A line has two characteristics1. Slope2. Points that fall on the line

Converting linear Converting linear equations into Slope-equations into Slope-

Intercept FormIntercept Form

5 Examples 5 Examples

Converting linear Converting linear equations into Slope-equations into Slope-

Intercept FormIntercept Form

5 Examples 5 Examples

Slope intercept form is:

y = mx + b

Our main goal is to get the y alone on one side of the

equation

Example 1 - convert into slope-intercept Example 1 - convert into slope-intercept formform


2 4 2y x 2 2 2

(divide both sides by 2 to get y alone)

(now simplify all fractions)

2 1

2 1y x

Slope (m) = 2

y-intercept (b) = 1

(divide both sides by 5 to get y alone)


y = 2x + 3 BRAVO!!

Slope (m) = 2

y-intercept (b) = 3

5y = 10x + 15

*** Your turn – Example 2 – convert

into slope-intercept form ***

5 5 5

2 3

*** Your turn – Example 3 – convert

into slope-intercept form ***

-3y = -9x – 12Step 1: divide both sides by -3 to get y alone

Step 2: Simplify all fractions

Step 3: Write your equation in y = mx + b

Slope (m) =

y-intercept (b) =

*** Check Your Answer ***

(divide both sides by -3 to get y alone)


y = 3x + 4

-3y = -9x – 12-3 -3 -3

Slope (m) = 3

y-intercept (b) = 4

21x – 7y = 14(subtract both sides by 21x)

-7y = -21x + 14 (divide both sides by -7)

y = 3x – 2(simplify all fractions)

Slope (m) = 3

y-intercept (b) = -2



-21x -21x

-7 -7 -7

3 2

2y + 26 = -6xStep 1: Subtract both sides by 26

Step 2: Divide both sides by 2 to get y by itself

Step 3: Simplify all fractions

Slope (m) =

y-intercept (b) =



2y + 26 = -6x(subtract both sides by 26)

2y = -6x – 26(now divide both sides by 2

y = -3x – 13

(simplify all fractions)

*** Check Your Answer ***

26 -26

2 2 2

Slope (m) = -3

y-intercept (b) = -13

HW#3• Q 1 – 9: Similar to WU• Q 10 – 15: What we did today

(solve for y)• Question 17 – 19: First find slope

from the two points (using rise/run), then find the b (where the line crosses the y-axis.)

Fri, 2/22/10

http://nlvm.usu.edu/en/nav/frames_asid_332_g_4_t_2.html?from=category_g_4_t_2.html

SWBAT… Write lines in slope-intercept form Thursday, 1/21/10

Agenda1. Warm-up (2 min)2. Review hw#3 (10 min)3. Brain Pop video & quiz (8 min)4. Review for test (30 min)

WARM-UP1. Take out hw#32. Take out study guide

STUDY FOR FINAL!!!

• Red Cards = #1

• Black Cards: Insert a 1 in front of number. For example, a black 2 = 12.

SWBAT… Write lines in slope-intercept form Tues, 1/19/10 Agenda 1.WU (5 min) 2.Graphing Calculator Activity (30 min) 3.Discussion (15 min) 4.Exit slip.

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