Warm Up

Mardi 5 octobre

Order the following numbers from least to greatest.

√36, -√2, (-0.4)2 , -3, 15%, √3

Mercredi 6 Octobre

Warm up

A linear function has a y-intercept of 3 and a slope of 5. What's the right function rule?

A. y = 5x + 3 C. y = 3x + 5

B. y = 8x D. y = 5*3x

Using linear function to predict the future...

Example 1: Baby's height and age

A baby is 20 inches long at birth. Assuming her growth is linear with a slope (or rate) of .25 inches per month, how tall will the baby be when he'll turn 2 ?

Could we solve this problem with 8th grade tools...

f(x) = ...... x + .......f(24) =

·Being able to write a linear function rule knowing the slope and the coordinates of one point can be very helpful to predict the future.

·This will be the 1st objective we will work on this week

Writing equations in slope intercept form

Obj. 1 : Knowing the slope and 1 point

Ex: Write the linear equation of a line with a slope of 3 and going through (2, 8)

Step 1: Write the general form of a linear equation

y = mx + b

Step 2: Write the value of the slope for m in the equation

here y = 3x + b

Step 3: Plug in the coordinates of the point for x and y in order to find b

8 = 3*2 + b

8 = 6 + bStep 4: Write the equation in slope

intercept form

Guided practice

Ex 1: Find the linear equation of a line going through (1, 4) with a slope of 2

Ex 2: Find the linear equation of a line going through (-2, 5) with a slope of 4

Independent Practice

2

3

2

Extra help :

1)Write the linear equation of the line with a slope of 2 and passing through (3, 10)

2) Write the linear equation of the line with a slope of -3 and passing through (1, 4)

Jeudi 7 Octobre

Warm up

Which line has a slope of 3 and passes through the point (1, 8)

A. y = 5x + 3 C. y = 3x + 5

B. y = 3x + 8 D. y = 1x + 8

Homework check and correction

Example 2: movie ticket price

A movie ticket price cost $5.50 in 2000. It costs in 2010, $8 on average. Assuming the increase in price is linear and will continue to be, how much will a movie ticket cost in 2023?

Correction

·In situations like these, it could be very helpful to be able to write the function rule knowing the coordinates of the 2 points.

·This way, we can use the function rule to predict the future..

·Writing a function rule knowing the coordinates of 2 points will be our 2nd goal this week!

Writing equations in slope intercept form

Obj. 2 : Knowing 2 points the line passes through

Ex: Write the linear equation of a line passing through

(1,2) and (3,8)

Step 1: Write y=mx +b

Step 2: Find the slope using slope formula

Step 3: Plug in slope into function rule

Step 4: Use one of the 2 points to find b

Step 5: Write function rule

Guided practiceEx 1: What is the linear equation of the line passing through (2, 4) and (3, 8) ?

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Ex 2: What is the linear equation of the line passing through (-1, 4) and (2, 10) ?

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Extra help : guided practice

Find the slope of the line going through

1. (1,3) and (2,8)

2. (3,5) and (6, 14)

Independent practice 2

Going further....

Vendredi 8 Octobre

Warm up

Write the linear equation of the line going through (3,8) and (-1, 0)S1 S5:

S2

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Homework correction

Independent practice 1

For each of the following 4 problems, find the linear equation of the line going through the 2 given points

1. (2,6) and (4, 10) 2. (3, 7) and (1, 13)

3. (1,-3) and (-4, 2) 4. (-1,-4) and (2, 11)

Obj. 1: slope and 1 point

Obj. 2: 2 points

Review activity

1. Write the linear equation of the line going through (2,8) with a slope of 3

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2. Write the linear equation of the line going through (1, 5) with a slope of -2

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3. Write the linear equation of the line going through (1, 5) and (3, 9)

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4. Write the linear equation of the line going through (-2,6) and (0,-2)

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5. Write the linear equation of the line going through (-4,-10) with a slope of 5

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6. Write the linear equation of the line going through (-1 , -3) and (1 , 7)

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Quiz #4

1. Write the linear equation of the line passing through (1,4) with a slope of 3

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2. Write the linear equation of the line passing through (3,8) and (7, 20)

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