Today:• Collect p291

Assignment• Return 5.1-3 Quiz• 5.5 Instruction• Practice

No trumpets sound when the important decisions of our life are made. Destiny is made known silently.

Agnes DeMille

Algebra 1

Assignment:• 5.3 p288 #19-37

odd, 46, 47, 51, 52

• MidTerm Progress Report Signature

• Goal Evaluation• Quiz 5.1-3

Tomorrow

No trumpets sound when the important decisions of our life are made. Destiny is made known silently.

Agnes DeMille

Algebra 1

Assignment:• 5.3 p288 #3-19

odd, 21-35, 46, 47, 51, 52

• MidTerm Progress Report Signature

• Goal Evaluation• Quiz 5.1-3

Tomorrow

No trumpets sound when the important decisions of our life are made. Destiny is made known silently.

Agnes DeMille

Algebra 1

CHECK UPFind the equations of the lines. Use slope-intercept

form.

5.3

16) (7, and 32) (5, through passes that line the 1.

(-18,-12) and 15)- (-12, through passes that line the 2.

(2,-30) and 5)- (2, through passes that line the 3.

5. A sports camp charges a registration fee and a daily amount. If a total bill for 12 days is $338 and for 19 days a bill is $506, find the equation that determines the charges for this camp. How much would 30 days cost?

72x8y

21x 21

y

2x

50x24y

3) (8, through passes and 2 -x 32

y to larperpendicu 4. 15 x

23

y

$770

5.1-3 Quiz

Objectives:

1. Use point-slope form to write equations of lines

2. Use point-slope form to model real world problems

 

Vocabulary: point-slope form

Point-Slope Form of a Linear Equation

5.5

• Slope-Intercept form– Used to graph a line– Used to find equations of lines

• Point-Slope form– Used to find equations of lines

Point-Slope Form of a Linear Equation

5.5

y = mx + b

slope

point (x1, y1)

y - y1=m(x - x1) y1 x1m

How to use Point-Slope form:

1. find slope, m, and a point (x1, y1)

2. plug values into the equation3. distribute and add (slope-intercept form)

y - y1 = m(x - x1)

Find the equations of the lines:

through (-10,-9) and (5,0)

through (-3,4) and (-3,11)

Example 1 Writing an Equation of a Line

3 x 53 y

3x

Example 2 Writing an Equation of a Line from a Graph

Write the equation of the line shown in the graph using point-slope form.

1 2 3 4 5 6 7

123

56

4

7

-6

-2

-4

-6-4 -2

27

x 23 y

5x

2y

What do we need to find the equation of a line?

– slope and a point

How do we find slope?

1. 2 points2. Parallel to another line (same slope)3. Perpendicular to another line (opposite

reciprocal slope)

Point-Slope Form of a Linear Equation

5.5

Example 3 Writing an Equation of Perpendicular Lines

Write the equation of the line that is parallel to the line y = -3x – 2 and passes through the point (3, -4)

3). (8, through passes and 2 -x 32

y to

larperpendicu is that line the of equation the Write

15 x 23

y

5 x 31

y

Example 4 Real Life Linear Models

A crate can hold up to 30 oranges. The crate with 16 oranges weighs 8.8 lb. Assuming that each orange weighs about .4 lb, write a linear model to represent the weight of a crate of x oranges.

y = .4x + 2.4

How much will a full crate weigh?

14.4 lb

Example 4 Real Life Linear Models

The base rent on a 5000 sq ft retail space is $40,000 per year. For larger spaces, any increase of 50 ft2 above the 5,000 ft2 results in an additional $300 per year in rent. Use the informatino to write a linear model for rent.

y = 6x + 10,000

Use the model to find the rent on a 6400 ft2 retail space.

$48,400

Example 4 Real Life Linear Models

The best temperature for running is below 60°F. If a person ran optimally at 17.6 ft/sec, he or she would slow by about .3 feet per second for every 5° increase in temperature above 60°F. Write an equation of this linear model.y = -.6x + 21.2

What is the running pace at a temperature of 80°F.

16.4 ft/sec

What do we use slope-intercept form for?

– Graphing a line– Finding the equation of a line

What is point-slope form for?

─ Find the equation of a line

What do you need to find the equation of a line?

─ Slope and a Point

Assignment:

5.5 p303 #3-17 odd, …5.5

Assignment:• 5.5 p303 #3-17

odd, 21-37, 48, 51-55 odd,

• Chapter 5 Test on Tuesday

No trumpets sound when the important decisions of our life are made. Destiny is made known silently.

Agnes DeMille

Algebra 1

1. textbook2.pencil3.binder w/dividers4.paper5.graph paper6.calculator7. colored pencils