Download Graphing using Slope - Baldwin School District

Name________________________________________Date______________8th Grade
Aim
How do we identify the slope and y-intercept of a line?
Warm Up
Graph each function.
1.
3.
y = 3x – 2
y = -2x + 3
2.
y=
1
x+1
2
Notes
Linear Equations are equations for which the graph is a straight line.
Slope
Slope describes the steepness of a line.
The slope of a line can be expressed as the ratio of the rise,
which is the vertical change, to the run, which is the horizontal
change.
If the slope is negative, that means the line has a negative rise,
which is a drop.
X and Y intercepts
The x-intercept is the x-coordinate of the point where the graph
crosses the x-axis.
The y-intercept is the y-coordinate of the point where the graph
crosses the y-axis.
Whole Group Questions
The slope and y-intercept can be used to graph a function or identify a function.
Look back at the warm up to find the slope and y-intercept in the equations below.
Equation
y = 3x – 2
y=
1
x+1
2
y = -2x + 3
Slope
y-intercept
A linear equation is in slope intercept form when it is written in the form:
y = mx + b
1.
What does m represent?
2.
What does b represent?
3.
Graph each function and state the slope and y-intercept.
A.
y = -4x + 5
B.
y=
1
x–1
3
Group Work Questions
1.
2.
State the y-intercept and slope for each linear equation below.
2
x–3
5
A.
y = 5x + 7
B.
y=
C.
y = -4x + 6
D.
y = 2x – 4
Which linear equation above:
A.
Is the steepest?
B.
Is the flattest?
C.
Has a negative rise or a drop?
Homework
Graph each function and state the slope and y-intercept.
1.
y = -3x + 3
2.
y=
1
x–1
4