Download SMART Notebook - Bakersfield College

Math 60 chapter 3 1pm.notebook
October 02, 2013
3.3 Graphing Using Intercepts
Definition:
x-intercept is where the graph
intersects the x-axis.
y-intercept is where the graph
intersects the y-axis.
10
y
8
6
4
Ex: Find the following on the given graph.
2
x
1) x-intercepts
-6
-5
-4
-3
-2
-1
0
-2
1
2
3
4
5
6
-4
-6
-8
2) y-intercept
-10
May 18-8:12 PM
1
Math 60 chapter 3 1pm.notebook
October 02, 2013
Finding intercepts from an equation:
To find x-intercept set y = 0 & solve for x.
To find y-intercept set x = 0 & solve for y.
Remark: In the last section we learned how to graph a line by plotting
points. It can be convenient to use the intercepts to help graph.
Ex: Find the intercepts and a third
check point to help graph the
equation
5x - 6y = 30.
y
x
May 18-9:45 PM
2
Math 60 chapter 3 1pm.notebook
October 02, 2013
Ex: Find the intercepts and a third
check point to help graph the
equation
3x - 4y = 8.
y
x
May 18-9:55 PM
3
Math 60 chapter 3 1pm.notebook
Ex: 3x + 5y = 0
October 02, 2013
3) Graph
1) Find the x-intercept.
y
2) Find the y-intercept.
x
May 18-9:58 PM
4
Math 60 chapter 3 1pm.notebook
October 02, 2013
Two Special Lines
Consider x = 4.
Q: Does the variable y exists in this equation?
y
Find 5 points that satisfy the
equation and graph.
6
5
4
3
2
1
-6
-5
-4
-3
-2
-1
0
-1
x
1
2
3
4
5
6
-2
-3
-4
-5
-6
May 18-10:02 PM
5
Math 60 chapter 3 1pm.notebook
October 02, 2013
Consider y = 4.
Find 5 points that satisfy the
equation and graph.
6
y
5
4
3
2
1
x
-6
-5
-4
-3
-2
-1
0
-1
1
2
3
4
5
6
-2
-3
-4
-5
-6
May 18-10:19 PM
6
Math 60 chapter 3 1pm.notebook
October 02, 2013
Ex: Graph
1) x = -2
2) 3x = 6
3) x + 2 = 7
5) 2y + 5 = 9
4) y = -3
May 18-10:20 PM
7
Math 60 chapter 3 1pm.notebook
October 02, 2013
Ex: Given the point (4, 6).
1) Graph the vertical line through the point.
10
y
2) Find equation of vertical
line through the point.
8
6
4
2
x
-10
-8
-6
-4
-2
0
-2
2
4
6
8
10
-4
-6
-8
-10
May 18-10:23 PM
8
Math 60 chapter 3 1pm.notebook
October 02, 2013
Ex: Given the point (4, 6).
1) Graph the horizontal line through the point.
10
2) Find equation of horizontal
line through the point.
y
8
6
4
2
x
-10
-8
-6
-4
-2
0
-2
2
4
6
8
10
-4
-6
-8
-10
May 18-10:23 PM
9