Algebra 8.2
Notes #27
Deciding whether an
Exponential Function
represents
Growth or Decay
Algebra 8.2
Notes #27
Deciding whether an Exponential
Function represents Growth or Decay
Simplify each by getting rid of the negative exponent:
[use your calculator. No Decimals. No Mixed Numbers.]
RECAP:
Examples:
Examples:
Notice in Examples 1­5, all the bases are greater than 1
For #6­#9:
Notice that the original base fraction is less than 1.
You need to make the base greater than 1 to see the actual transformation.
Examples:
Evaluate each expression:
No Decimals. [use your calculator to find exact answers] No Mixed Numbers
1.
5.
9.
2.
6.
10.
3.
7.
11.
4.
8.
=
12.
13. The student enrollment, E, of a high school was 1240 in 2004 and increased
by 15% per year until 2016. Which exponential growth model shows the
school's student enrollment in terms of t, the number of years since 2004?
(Multiple choice)
14. Which function is graphed
below?
15. Which function is graphed
below?
16. The value (V) of a car that was bought in 2012 has been depreciating
(decreasing) by 9% each year. You bought the car for $13,500.
Which exponential decay model shows the car's value after t years?
(Multiple choice)
Note: All Base numbers must be greater than 1 before giving answer
Questions 17­34: State whether the function f(x) is an exponential growth
function or exponential decay function: [write either "Growth" or "Decay"]
17.
18.
19.
20.
21.
22.
23.
24.
25. f(x)= ­5 6x
NOTE:
If BASE >1,
then you
can look
and decide
if Growth
or Decay
NOTE:
If BASE <1,
you have to
change the
base to a
number > 1
before
deciding
what you
have
[Growth or
Decay]
26.
27.
28.
29.
30.
31.
If Base > 1, then
What kind of function
do you have if you have
one negative sign?
2 negatives make a
3 negatives make a
32.
33.
what type of
function is this?
Growth or Decay?
Notice: 3 negatives
mean that 2 cancel and
1 remains.
What type of function
is this?
Algebra 8.2
Notes #27
Deciding whether an
Exponential Function
represents
Growth or Decay
Algebra 8.2 Deciding whether an Exponential
Notes #27 Function represents Growth or Decay
Simplify each by getting rid of the negative exponent:
[use your calculator. No Decimals. No Mixed Numbers]
RECAP:
Examples:
Examples:
Notice in Examples 1­5, all the bases are greater than 1
For #6­#9:
Notice that the original base fraction is less than 1.
You need to make the base greater than 1 to see the actual transformation.
Examples:
Evaluate each expression:
No Decimals. [use your calculator to find exact answers] No Mixed Numbers
1.
5.
9.
2.
6.
10.
3.
7.
11.
= 25 =
4.
8.
12.
= 64 =
=
13. The student enrollment, E, of a high school was 1240 in 2004 and increased
by 15% per year until 2016. Which exponential growth model shows the
school's student enrollment in terms of t, the number of years since 2004?
(Multiple choice)
14. Which function is graphed
below?
15. Which function is graphed
below?
16. The value (V) of a car that was bought in 2012 has been depreciating
(decreasing) by 9% each year. You bought the car for $13,500.
Which exponential decay model shows the car's value after t years?
(Multiple choice)
Note: All Base numbers must be greater than 1 before giving answer
Questions 17­34: State whether the function f(x) is an exponential
growth function or exponential decay function:
17.
18.
19.
20.
21.
22.
23.
24.
25. f(x)= ­5 6x
NOTE:
If BASE >1,
then you
can look
and decide
if Growth
or Decay
NOTE:
If BASE <1,
you have to
change the
base to a
number > 1
before
deciding
what you
have
[Growth or
Decay]
26.
27.
28.
29.
30.
31.
If Base > 1, then
What kind of function
do you have if you have
one negative sign?
Decay
2 negatives make a
positive
3 negatives make a
negative
32.
33.
what type of function
do you think this is?
Growth or Decay?
Growth
Notice: 3 negatives
mean that 2 cancel
and 1 remains.
What is this function
type?
Decay