Exponential Functions Intro
Identify BOTH
exponential functions
 y = 2x3
 y = 3x2
 y = 3 • 2x 
 y = 2 • 3x
Yes, Exponential         NO WAY !!!
y = 7 • 5x
?
y = 0 • 5x
?
Yes, Exponential         NO WAY !!!     
y = 9•(4)x
?
y = 9•(-4)x
?
Yes, Exponential      NO WAY !!!
y = 3 • 5x
?
y = 3 • 1x
?
         Is NOT an exponential function.    Multiplying by 1 repeatedly does not CHANGE (grow or decay) the initial value.  
y = 3 • 1x  
Other exponential functions: 

A function such as y=2

is an exponential function.

x
y = 3
y = (4.2)
y = (½)
x
x
x

A function such as y=2

is an exponential function.

Which is NOT an 

exponential function: 

Exponential  Function
y = 3x
y = (4.2)
y = (¾)
x
x
x
y = 3x is NOT an exponential function.  
            It is a linear function.    

A function such as y=2

is an exponential function.

y = 3x
x

Thanksgiving

-style,

Set a Table

But Mr.!  How do I graph Exponential

Functions?!!!

x

0

1

2

3

x

Drag in x values

so you can find 3

3

3

3

0
?
1
?
2
?
x

Hint:

Any #

raised to

the zero

power

equals 1

x

0

1

2

3

1
?
9
?
3
?
x

3

3

3

0
1
2

Drag

the

correct

values

in the

table

x

0

1

2

3

1
3
9                                                                                      
x

This is

an exponential

function graph

x

0

1

2

2

1

?

4

?

2

?
x

Is an exponential function

fill in the x values to

make a new power of 2.

y = 2

x
2
-2
4
-4
2
-2
4
-4
6
-6
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x
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0

1

2

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2

1

2

4

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x
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Click a

dot to

plot

(0,1)

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2
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-6
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x
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0

1

2

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2

1

2

4

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x
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Click a

dot to

plot

(1,2)

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2
-2
4
-4
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-2
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-4
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-6
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x
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0

1

2

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2

1

2

4

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Click a

dot to

plot

(2,4)

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2
-2
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-4
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-2
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-4
6
-6
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x
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0

1

2

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2

1

2

4

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x
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Exponential

graphs

 are

curved

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x

3

4

5

6

2

x-3
Fill in the table blanks

2

2

3
  -3

4

  -3
=
=

2

2

0

1

=
=
???
x

3

4

5

6

2

1

2

x-3
Fill in the table blanks

2

2

5

  -3

6

  -3
=
=

2

2

2

3

=
=
???
x

3

4

5

6

2

1

4

8

2

x-3

2

Completed table.

2

5

  -3

6

  -3
=
=

2

2

2

3

Which is the graph of

an exponential function?

Blue graph
Red graph
Green graph
x

0

1

2

3

(½)

½

?

¼

?

?

1

?
x

(½)

(½)

(½)

(½)

0
1
2
3
=
=
=

(½)

(½)

(½)

*
*

(½)

(½)

*

(½)

x

0

1

2

3

(½)

1

½

¼

x

(½)

(½)

(½)

(½)

0
1
2
3
=
=
=

(½)

(½)

(½)

*
*

(½)

(½)

*

(½)

Look at the graph for

y = (½)

When x = 0, y = 1
x
When x = -1  y = 

Look at the graph for

y = (½)

x
When x = -1  y = 2

Look at the graph for

y = (½)

x
When x = -2,  y =

Look at the graph for

y = (½)

x
When x = -2,  y = 4

Look at the graph for

y = (½)

x
Done
   &
Done
Altres proves d'interés :

Prova creada amb That Quiz — el lloc per crear proves matemàtiques i d'altres matèries.