Objective # 8
Drawing the Graph of a Linear Equation - Using the Slope and y-intercept
Material:
page 118 to 129
Homework:
worksheet
What is the smallest number of points needed to draw the graph of a line?
Example:
_________
For each of the following give the slope and y-intercept and use that information to draw
the graph of the line:
a)
slope =
rise = 2 run = 3
y-intercept = (0,-3)
Plot the y-intercept and from there we know
the second point is 2 up and 3 to the right.
b)
Example:
c)
d)
Rearrange the following equations to the slope-y-intercept form, give the slope and
y-intercept and use that information to draw the graph.
a)
4x + y - 5 = 0
1st
add 5 and subtract 4x from both sides
y = - 4x + 5 slope = - 4 rise = - 4 run = 1
y-intercept = (0, 5)
Plot (0, 5) and from there go down 4 and
right 1 to find the second point.
b)
2x - 5y + 25 = 0
1st
subtract 25 and 2x from both sides
2nd
divide every term by -5
`
slope =
Now draw the graph!
c)
e)
7x - 4y - 16 = 0
rise = 2
run = 5
y-intercept = (0, 5)
Draw the graph of a linear equation using the slope and y-intercept
Worksheet
1.
Give the slope and y-intercept of each of the following linear equations and use that information to
draw their graphs. Draw separate graphs.
a)
b)
c)
d)
e)
f)
g)
h)
i)
j)
k)
l)
2.
Rearrange the following equations to the slope-y-intercept form, give the slope and y-intercept and
use that information to draw the graph. Draw separate graphs.
a)
b)
c)
d)
e)
f)
g)
h)
Special lines:
Parallel lines are lines the are always the same distance apart.
Perpendicular lines are two line that intersect at right angles.
Can you guess a connection
between the slopes of parallel lines?
Can you guess a connection
between the slopes of perpendicular lines?