the slope intercept form y = mx + btoshmath421a.weebly.com/uploads/4/3/1/8/43188271/... · lesson...
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Lesson 6.5 (2).notebook
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December 12, 2014
Dec 105:31 PM
The equation of a line is it's "name"
Just like with people, we can have different names
Examples: #1. Mrs Craig, Tammy, TCraig, mom #2. Jonathon, John, Jonny
So far, we've learned how to use one name of a line
The slope intercept form y = mx + b
Lesson 6.5 (2).notebook
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December 12, 2014
Dec 105:35 PM
For example:
y = 2x + 3has a slope of 2 and a yintercept of 3
The "name" of this line is it's equationBut we could give it a nickname, or a different version of it's name.
Lesson 6.5 (2).notebook
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December 12, 2014
Dec 105:36 PM
Chapter 6.5 Teaches us the slopepoint form of a linear equation
In Chapter 6.4, we learned the slopeintercept form of a linear equation
Why is it called the slopeintercept form?
y = x 7 32
What information do you think we'll know from this form of the equation?
y y1 = m(x x1)slopepoint form
Lesson 6.5 (2).notebook
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December 12, 2014
Dec 105:42 PM
where the line passes through the point (x1, y1) and has a slope of m
slope point form
example#1: What is the equation of a line that has a slope of 4 and passes through the point (2, 7)?
So why would this be a useful form?
When we don't know the y‐intercept
Lesson 6.5 (2).notebook
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December 12, 2014
Introduction
What other equations related to lines do we currently know?
Suppose you could not identify the y intercept
Lesson 6.5 (2).notebook
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December 12, 2014
Jan 95:55 PM
Point Slope Form:
Ex(2) State the slope of the line and a point on the line
Ex(4) Write the equation of the linear function that has a slope of 4 and passes through the point (3, 7).
5
Ex(3) State the slope of the line and a point on the line
y 5 = (x 3) 52
Lesson 6.5 (2).notebook
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December 12, 2014
Example 1
ç ?
(By describing the graph it means to tell what the slope is and the coordinates for 1 point on the line.)
Ex(5) Point Slope Form:
Lesson 6.5 (2).notebook
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December 12, 2014
Dec 2911:56 AM
Ex #6 (a) Graph the line with the equation
(b) Rewrite the equation in slope intercept form and state the yintercept. This means rearrange the equation!
Point Slope Form:
Point Slope Form: Slope Intercept form: y = mx + b
Lesson 6.5 (2).notebook
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December 12, 2014
Jan 16:25 PM
A) Write the equation of a line that passes through the point (2,5) and has a slope of 4.
B) Rearrange the equation in part A into slope-intercept form. What is the y-intercept of this line?
You try it:
Lesson 6.5 (2).notebook
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December 12, 2014
Dec 133:02 AM
In the equation y 4 = 3(x 2), the slope and point of intersection are...
1
m = 3 point: ( 2, 4)
m = 4 point: ( 2, 4)
m = 3 point: (2, 4)
m = 4 point: (2, 4)
A
B
C
D
Lesson 6.5 (2).notebook
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December 12, 2014
Dec 133:02 AM
2 Write the equation for the line that passes through (1, 5) and has a slope of 4.
y 5 = 4 ( x + 1)
y 1 = 4 ( x + 5)
y + 1 = 4 ( x 5)
y + 5 = 4 ( x 1)
A
D
C
B
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December 12, 2014
Dec 133:02 AM
3 Which graph matches the equation y 1 = 1/2(x 2)?
A B
Lesson 6.5 (2).notebook
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December 12, 2014
Jan 16:43 PM
HOMEWORK QUESTIONSPAGES 372374
DO #'S: 4, 5, 6, 9, 11a,b, 14,
DUE TOMORROW!!
+
Lesson 6.5 (2).notebook
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December 12, 2014
Dec 105:52 PM
Place these equations into slopeintercept form
#1. 2y 7x + 12 = 0
#2. y 4 = (x + 5)
Lesson 6.5 (2).notebook
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December 12, 2014
Dec 2911:45 AM
(a) Write the equation of this line in slopepoint form.
(b) Rewrite the equation from part (a) into slopeintercept form.
Review from yesterday:
Lesson 6.5 (2).notebook
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Dec 105:54 PM
Questions from homework?
HOMEWORK QUESTIONSPAGES 372374
DO #'S: 4, 5, 6, 9, 11a,b, 14,
Lesson 6.5 (2).notebook
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December 12, 2014
Jan 16:34 PM
When you are only given two points on a line you must calculate
the slope first and then proceed like we did in the previous
example.
Write an equation of the line that passes through the points (-2, 30) and (2, -5). Express your answer in slope intercept form.
Ex(#1)
Lesson 6.5 (2).notebook
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December 12, 2014
Dec 105:54 PM
Ex #2: Write an equation of the line that passes through the points (1, -4) and (2, 3). Express your answer in slope intercept form.
Lesson 6.5 (2).notebook
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December 12, 2014
Dec 2911:47 AM
Write an equation of the line parallel to y = 2x +1 and that goes through the point ( 2, 1).
Lesson 6.5 (2).notebook
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December 12, 2014
Dec 2912:52 PM
Write an equation, in slopeintercept form, of the line
perpendicular to and that passes through ( 1, 3).
Lesson 6.5 (2).notebook
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December 12, 2014
Dec 291:23 PM
Linear Functions
Slope-InterceptForm
y = mx +b
Slope-Point Form
y- y1 = m(x -x1)
Must know the slope (m) and
y-intercept (b)
Must know * two pts or
* one pt and the slope
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Dec 116:48 PM
20a, 21, 23.
page 374