Download 4. 3 Graph using Intercepts

3.1 Graph using
Intercepts
Objective: Graph a linear
equation using intercepts
and by making a table
Intercept
x- intercept
- where the line
crosses the x-axis
y-intercept
- where the line
crosses the y-axis
Page 154 example 2
Page 155
Example 3
Draining a Pool
Time
(h)
Volume
(gal)
X
Y
0
10,080
2
8640
6
5760
10
2880
12
1440
14
0
A swimming pool is being
drained at a rate of 720
gallons per hour. The
table shows the
function relating the
volume of water in a
pool and the time in
hours that the pool has
been draining.
Page 157 #5
and 6
Finding the
x- intercept
1) Substitute 0 for y
2) Then solve for x
3) (x, 0)
Finding the
y-intercept
1) Substitute 0 for x
2) Then solve for y
3) (0, y)
Find the x and y
intercepts Then graph
the line
3x+ 2y= 6
Find the x and y
intercepts Then graph
the line
y=x+3
Find the x and y intercepts
Then graph the line
y= 1x+2
3
p. 159 #50
An amusement parks charges $50 for admission
before 6pm and $20 for admission after 6pm. On
Saturday, the park took in a total of $20,000.
a) Write an equation that represents the number of
admissions that may have been sold. Let x
represent the number of admissions sold before
6pm, and let y represent the number of admission
sold after 6pm.
b) Graph the equation
c) Find the x- and y-intercepts of the graph. What
does each intercept represent
Journal
Can a line only have one
intercept or must it always
have an x-intercept and a
y-intercept?
Homework
Page 157-158
#’s 19-34 odd