Download 1.7 Represent Functions as Graphs Example 1

1.7 Represent Functions as Graphs
Goal • Represent functions as graphs.
GRAPHING A FUNCTION
•
You can use a graph to represent a _______________.
•
In a given table, each corresponding pair of input and output values forms an______________.
•
An ordered pair of numbers can be plotted as a _____________.
•
The x -coordinate is the ____________.
•
The y -coordinate is the _____________.
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The horizontal axis of the graph is labeled with the ___________________.
•
The vertical axis is labeled with the the ___________________.
Example 1 -
Graph a function
Graph the function y = x + 1 with domain 1, 2, 3, 4, and 5.
Step 1 Make an _____________________________ table.
x
y
Step 2 Plot a point for each ___________________________ (x, y).
Step 3 Draw a line to connect the points if needed.
What is the range of this function?
Example 2 -
Graph a function
Graph the function y = 2x - 2.
Step 1
x
Step 2
y
Since the domain is not given, we choose values. A good rule
is to choose two negative values, 0 and two positive values.
Step 3 Draw a line to connect the points if needed.
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1
What is the range of this function?
Now You Try It!
1) Graph the function y = x + 2 with domain 1, 2, 3, 4, and 5
x
y
What is the range of this function?
2) Graph the function y = 2x + 1.
x
y
What is the range of this function?
Example 3 –
Putting it all together. The admission for students to go to Water Works is $24 per
person. The cost of the busses for the entire 7th grade is $450.
a) Write an equation or rule that represents the function.
b) Make a table that shows how much a
trip for 50 students, 100 students,
150 students, 200 students, and 250
students would cost.
e) What is the range?
x
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c) Graph the application.
Don’t forget:
Title
Label x and y axis with name
Label values
Decide if your line should be
connected.
d) What do you notice about the
starting value?
2
y
Now You Try It!
ABC Package company charges a flat rate of ten dollars to box any item and then a charge of 5
dollars per pound to ship.
a) Write an equation or rule that represents the function.
b) Make a table that shows the cost
of shipping a 5 pound, 10 pound,
15 pound, 20 pound and 25 pound
package.
x
y
c) Graph the application.
d) What do you notice about the
starting value?
e) What is the range?
Example 4 – The Vertical Line Test
If you are looking at a graph and want to decide if it is a function, you can use the “vertical line test”.
d) Why does the this test work?????
3
c) Function?
b) Function?
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a) Function?