# slope intercept form3

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Jeudi 23 Septembre

Warm up

A tennis club membership costs $5 a year. In addition to this flat fee, you must pay $2 every time you reserve a court. Which function rule describes the cost (y) for the number of times you reserve a court(x)

A. y = 7B. y = 5x + 2C. y = 7xD. y = 2x + 5

xy0123y = 2x + 5

Slope intercept form of linear functions

We have learned that every linear function can be expressed by a function rule that looks like this :

y = ___ x + ___

In algebra, we call this form of function rule a slope intercept form.

You'll find it usually expressed as

y = mx + b

y and x are variables. They vary!m and b are numbers, constant. They stay the same!

40% of the 8th grade math EOG questions, are about finding the value of m or b using:

The graphThe function ruleCoordinates of 2 pointsa real life situation

So let's say it's a... VERY important lesson!

b a.k.a the y-interceptFor the real life situation, b is always the flat fee,the guaranteed salary... Basically the part of the cost (salary) that does not depend on the other variable

On the graph, you can always read it where the line intersects the y-axis. Therefore it's called the y intercept!

y = mx + .....y = mx + ......Guided practice

Independent practiceFind the y-intercept of each linear function

Vendredi 24 Septembre

Warm up

What is the y-intercept of the following lines?

What is the slope of a line?Slope: The number that determines the steepness of a line

Where do we see natural slopes???

Watch the 2nd video and try to take notes of the 4 different types of slope.

Slopes can be:positivenegativezeroundefined*Look at the line from left to right (like reading)

cross country skiing

Is the slope positive, negative, undefined or none at all???

Is the slope positive, negative, undefined or none at all???

Is the slope positive, negative, undefined or none at all???

Is the slope positive, negative, undefined or none at all???

Is the slope positive, negative, undefined or none at all???

Is the slope positive, negative, undefined or none at all???

Is the slope positive, negative, undefined or none at all???

Is the slope positive, negative, undefined or none at all???

Is the slope positive, negative, undefined or none at all???

Review game

Lundi 27 Septembre

Warm up1) What is the y-intercept of this line?

2) Is the slope of this line positive, negative zero or undefined?

Quick review: What do we know so far on linear functions ?

Objective 1: Finding slope on the graph

Watch the following segment of video (what is slope from 2:00 mark) and write down steps to find the slope of a line on the graph.

Finding slope on the graph step by step

Step 1: Determine sign of the slope (+,-,...)

Step 2: Pick 2 points on the line(corners of unit squares)Step 3: Draw a slope triangle Rise first,run second. Rise : up +, down - Run : right +, left -Step 4: Write the fraction rise/run, simplify, check the sign

Guided practice

Step 1:

Step 2:

Step 3:

Step 4:

Step 1:

Step 2:

Step 3:

Step 4:

Independent practice: (will be evaluated)

Front: The 2 points are already picked for you (step 2), focus on the 3 other steps.

Back page: You have to pick the 2 points, remember to pick them on corners of unit squares

Chek with your partners, ask for help, do not stay passive. 90% of the learning happens here!

Mardi 28 SeptembreWarm up

Homework check

Objective 2: Matching a linear equation with a graphWhich linear equation describes the blue line?A. y = 3x + 2B. y = -3x - 2C. y = 3x - 2D. y = 4x - 2Step 1: Find the y-intercept of the blue line. Eliminate answers based on the "b".

Step 2: Determine sign of slope. Eliminate answers based on the sign of "m"

Step 3: Find slope. You should have only one possible answer

Independent practice

Y = mx + b

Objective 2: Which linear equation describes the blue line?

A. y = (2/3)x + 2B. y = ( -3/2)x+ 2

C. y = (3/2)x - 3D. y = (-2/3)x+ 2

Which graph corresponds to y = (1/2)x - 1 ?

Pop quiz 3

End of class game

Mercredi 29 Septembre

Warm up y = 2x + 1?

Pop quiz 3for the same 4 graphs, write the function rule

Homework check

Objective 3: Find the slope of a line knowing the coordinates of 2 points

What is the slope of a line going through (1,2)and (3,6) ?

Could we do this without graphing?

Objective 3: Find the slope using coordinates of 2 points

Step by step guided practiceStep 1: Mark (x1 , y1) and (x2 , y2) under the points.

Step 2: Write down the formula

Step 3: Plug in the numbers in your formula. Simplify

Find the slope of the line that goes through the two points given.

1.2.TRY:

Find the slope of the line that goes through the two points given.

Jeudi 30 Septembre

Warm up

Find the slope of the line going through the following points

Homework check

Quiz 3 : study guideObj 2: Match y=mx+b with graph

Objective 1 example problemS1:

S2:

S3:

S4:

Objective 2: example problem

Which function rule best describes the blue line?A. y = 1x + 2B. y = -2x + 1C. y = 0.5x +1D. y = 0.5x - 1S1:

S2:

S3:

Objective 3 example problem

Find the slope of the line going through (-1,3) and ( 5, 1)

S1:

S2

S3:

Review game

Everyone in the group does the work!

Rewards will go to the winners + the groups where I see REAL group work

Which line is best described by : y = -2x -1?

Which line best describes the function rule y = 1/2x + 1

Which function rule best describes the blue line?

A. y = 4x - 1B. y = 4x - 1

C. y = (-1/4)x + 1D. y = (-1/4)x - 1

Vendredi 1er Octobre

Warm up

Write the function rules that can describe the blue lines:

Quiz # 3

Objective 1: Find the slope of the following lines using the graph

Write the function rules that best describe the following lines:

6)7)Obj. 2: Match a function rule with a graph

8) Which function rule best describes the line?A. y = (1/2)x + 4

B. y = 4x + 2

C. y = -2x + 4

D. y = 2x + 4

9) Which function rule best describes the line?A. y = -1x - 2

B. y = -3x - 2

C. y = 1x + 2

D. y = 1x - 2

10) Which graph represents the function y = (-1/2)x + 3 ?

Find the slope of the lines going through:

11) (2,4) and (3,8)12) (-1, 3) and (4, -7)

13) (-2,5) and (1,5)14) (2,4) and (2,10)Obj. 3:

15) Round 46 to the nearest tenth

16) Is 5 rational or irrational?

17) Is 49 rational or irrational?

18) Put 96 between 2 consecutive integers

< 96