Exploring Exponential Models
Name
Class
Practice
7-1
Form G
Exploring Exponential Models
1 x
3. y 5 2 Q 5 R
Graph each function.
1. y 5 (0.3)x
6
Date
2. y 5 3x
y
6
y
y
4
4
2
2 x x
Ϫ2 O
2
Ϫ2 O
2
x
Ϫ2 O
1
4. y 5 2(3)x
5. s(t) 5 2.5t
y
6 s(t)
6 f(x)
4
2
4
6
4
1
6. f (x) 5 2(5)x
2
2
2
Ϫ2 O
x
t
x
2
1 x
7. y 5 0.99 Q 3 R decay; 0.99
Ϫ2 O
Ϫ2 O
2
2
Without graphing, determine whether the function represents exponential growth or exponential decay. Then find the y-intercept.
5 x
9. y 5 185 Q 4 R growth; 185
2 1 x
10. f (x) 5 3 Q 2 R decay; 2
3
8. y 5 20(1.75)x growth; 20
1 6 x
12. y 5 5 Q 5 R growth; 1
5
11. f (x) 5 0.25(1.05)x growth; 0.25
13. Suppose you deposit $1500 in a savings account that pays interest at an annual
rate of 6%. No money is added or withdrawn from the account.
a. How much will be in the account after 5 years? about $2007.34
b. How much will be in the account after 20 years? $4810.70
c. How many years will it take for the account to contain $2500? about 9 years
d. How many years will it take for the account to contain $4000? about 17 years
Write an exponential function to model each situation. Find each amount after the specified time.
14. A population of 1,236,000 grows 1.3% per year for 10 years. y 5 1,236,000(1.013)x ; about 1,406,413
15. A population of 752,000 decreases 1.4% per year for 18 years. y 5 752,000(0.986)x ; about 583,448
16. A new car that sells for $18,000 depreciates 25% each year for 4 years. y 5 18,000(0.75)x ; $5695.31
Prentice Hall Gold Algebra 2 • Teaching Resources
Copyright © by Pearson Education, Inc., or its affiliates. All Rights Reserved.
3
Name
7-1
Class
Date
Practice (continued)
Form G
Exploring Exponential Models
For each annual rate of change, find the corresponding growth or decay factor.
17. 145% 1.45
18. 210% 0.9
19. 240% 0.6
Class
Practice
7-1
Form G
Exploring Exponential Models
1 x
3. y 5 2 Q 5 R
Graph each function.
1. y 5 (0.3)x
6
Date
2. y 5 3x
y
6
y
y
4
4
2
2 x x
Ϫ2 O
2
Ϫ2 O
2
x
Ϫ2 O
1
4. y 5 2(3)x
5. s(t) 5 2.5t
y
6 s(t)
6 f(x)
4
2
4
6
4
1
6. f (x) 5 2(5)x
2
2
2
Ϫ2 O
x
t
x
2
1 x
7. y 5 0.99 Q 3 R decay; 0.99
Ϫ2 O
Ϫ2 O
2
2
Without graphing, determine whether the function represents exponential growth or exponential decay. Then find the y-intercept.
5 x
9. y 5 185 Q 4 R growth; 185
2 1 x
10. f (x) 5 3 Q 2 R decay; 2
3
8. y 5 20(1.75)x growth; 20
1 6 x
12. y 5 5 Q 5 R growth; 1
5
11. f (x) 5 0.25(1.05)x growth; 0.25
13. Suppose you deposit $1500 in a savings account that pays interest at an annual
rate of 6%. No money is added or withdrawn from the account.
a. How much will be in the account after 5 years? about $2007.34
b. How much will be in the account after 20 years? $4810.70
c. How many years will it take for the account to contain $2500? about 9 years
d. How many years will it take for the account to contain $4000? about 17 years
Write an exponential function to model each situation. Find each amount after the specified time.
14. A population of 1,236,000 grows 1.3% per year for 10 years. y 5 1,236,000(1.013)x ; about 1,406,413
15. A population of 752,000 decreases 1.4% per year for 18 years. y 5 752,000(0.986)x ; about 583,448
16. A new car that sells for $18,000 depreciates 25% each year for 4 years. y 5 18,000(0.75)x ; $5695.31
Prentice Hall Gold Algebra 2 • Teaching Resources
Copyright © by Pearson Education, Inc., or its affiliates. All Rights Reserved.
3
Name
7-1
Class
Date
Practice (continued)
Form G
Exploring Exponential Models
For each annual rate of change, find the corresponding growth or decay factor.
17. 145% 1.45
18. 210% 0.9
19. 240% 0.6