warm up add or subtract. 1. 4 + (–6)2. –3 + 5 3. –7 – 74. 2 – (–1) –2 –14 2 3 5....
TRANSCRIPT
Slope
Lesson 5.3
Objectives
• Graph linear functions, noting that the vertical change per unit of horizontal change is always the same and is called the slope of a line (AF 3.3)
• Fit a line to a plot and understand that the slope of the line equals the ratio of the quantities (AF 3.4)
• a nonvertical line is the ratio of the rise to the run between any two points on the line.
• Slope = “steepness” of a line.
run
rise
Slope –
Find the slope of the line.
Begin at one point and count vertically to find the rise.
Then count horizontally to the second point to find the run.
Run = 4
Rise =–2
Run = –4
Rise = 2
Riserun
Finding Slopes of Horizontal
and Vertical Lines A. B.
The slope is undefined. The slope is 0.
Real World Slope
Find the slope of the line
Find the slope of the line
How do you find the slope on the graph?
Kinds of Slopes
(It helps to remember how you would walk on these lines.)
Positive slope – walking up hill.
Negative slope – walking down a hill.
No slope – walking on level ground
Let’s practice- find the slope of the line.
2
1
4
3
13
21
)1(3
)1(2
Find a slope of two points
(2, 5) and (8, 1).(x1, y1) (x2, y2).
Use the slope formula.
Substitute (2, 5) for (x1, y1) and (8, 1) for (x2, y2).
Find a slope of two points
(5, –7) and (6, –4)(x1, y1) (x2, y2).
RiseRun
yx
5
6-7
-4+3
x y
+1
31
Find a slope of two points
(5, 3) and (–1, 4)(x1, y1) (x2, y2).
RiseRun
yx
5
-13
4+1
x y
-6
1-6
Find a slope of two points
(1, 3) and (–2, 1)(x1, y1) (x2, y2).
RiseRun
yx
1
-23
1-2
x y
-3
-2-3
23
And one last laugh…
Summary
• The constant rate of change of a nonvertical line is called the slope.
• If you know 2 different points on a line, you can use the slope formula to find the slope of the line
• If you know the equation of a line, you can also find the slope by using any two ordered-pair solutions
• Slope can be positive, negative, zero, and undefined
Lesson QuizFind the slope of each line.
undefined
1. 2.
Lesson Quiz –part 23. Find the slope of the line that contains (5, 3) and (–1, 4).
4. Find the slope. Then tell what the slope represents.
A slope of 50 means that the speed of the bus is 50 mi/h.
50
5. Find the slope of the line given by x – 2y = 8.