Post on 30-Dec-2015
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