Name _______________________________________ Date __________________ Class __________________ 1. Find the next three terms in this sequence: 5120, 1280, 320, 80, … A 160, 400, 640 B 20, 5, 1.25 C 40, 20, 10 D 76, 72, 68 2. The first term of a geometric sequence is 2 and the common ratio is 3. What is the 12th term of the sequence? F 1,062,882 H 6144 G 354,294 J 12,288 1 3. Which graph shows y 3 ? 4 A x 4. The function f(x) 50(1.2)x gives the number of bacteria in a science experiment, where x is the number of days after the start of the experiment. To the nearest whole number, how many bacteria will there be after 5 days? F 124 H 375,000,000 G 300 J 777,600,000 5. Which are the next three terms in the geometric sequence 216, 36, 6, 1, …? A 0, 1, 6 B C 1 1 1 , , 6 36 216 1 1 1 , , 3 6 9 D 6, 36, 216 6. Which is the 10 th term of the geometric sequence B 1 1 1 1 , …? , , , 512 256 128 64 F 1 H 1 4 1 2 J 1 8 G 7. Which is the 6th term of the geometric sequence 729, 81, 9,…? A 1 729 C B 1 81 D 1 C 1 9 8. Which ordered pairs satisfy an exponential function? F X Y 4 0 3 5 2 0 1 25 X Y 4 81 3 27 2 9 1 1 X Y 4 64 3 27 2 8 1 1 X Y 4 4 3 2 2 0 1 2 G D H J Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 1 Name _______________________________________ Date __________________ Class __________________ 9. Which set of ordered pairs satisfies an exponential function? A {(2, 1), (8, 2), (32, 3), (128, 4)} B {(1, 2), (0, 10), (1, 50), (2, 250)} C {(1, 2), (1, 6), (1, 18), (1, 54)} D {(1, 2), (2, 4), (3, 6), (4, 8)} 10. The number of members in a labor union is 240, and the number increases by 5% each year. Find the number of members after 4 years. F 278 H 810 G 292 J 1215 11. Iodine-131 has a half-life of approximately 8 days. Find the amount of iodine-131 left from a 100-gram sample after 16 days. A 0.0015 g C 25 g B 0.39 g D 32.75 g 12. Determine which kind of model best describes this data set. {(2, 1), (1, 2), (0, 4), (1, 8), (2, 16)} 13. Which of the following data sets is best described by a linear model? A {(2, 4), (1, 9), (0, 16), (1, 25)} B {(2, 1), (1, 0), (0, 1), (1, 0)} C {(2, 12), (1, 10), (0, 8), (1, 6)} D {(2, 1), (1, 0), (0, 1), (1, 4)} 14. Which of the following models best describes the data set? {(5, 2), (6, 0), (7, 2), (8, 8)} F linear H exponential G quadratic J none 15. Martin has $200 in his savings account. He wants to save more money. He is looking at two investment plans. Under plan A, he will increase his account balance by $40 a year. Under plan B, he will increase his account balance by 15% each year. How much more will he save with Plan B after 10 years? A $209 C $26 B $92 D $2 16. Which is the average rate of change over the interval [2, 3]? Equation A X Y 0 1 1 4 2 9 3 16 Equation B f ( x ) x 2 H A: 3, B: 1 F A: 7, B: 1 F linear H quadratic G exponential J none G A: 7, B: 1 J A: 1, B: 7 17. Which is the y-intercept of the equations? Equation A X Y 0 1 1 4 2 9 3 16 Equation B f ( x ) x 2 A A: 1, B: 1 B A: 2, B: 0 C A: 1, B: 2 D A: 1, B: 2 Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 1 Name _______________________________________ Date __________________ Class __________________ 1. Find the next three terms in this sequence: 224, 112, 56, 28, ... 5. Which are the next three terms in the geometric sequence 4, 2, 1, 0.5, …? ________________________________________ ________________________________________ 2. The first term of a geometric sequence is 5 and the common ratio is 2. What is the 10th term of the sequence? 6. Which is the 10th term of the geometric sequence 256, 128, 64, 16 , …? ________________________________________ 7. Which is the 6th term of the geometric ________________________________________ 3. Graph y 6(3)x. x sequence 1 , 1, 3,…? 3 y ________________________________________ 8. Fill in the ordered pairs that satisfy the exponential function. X Y 1 1 64 2 3 1 4 4 5 4 6 16 4. The function f(x) 30(1.4)x gives the number of bacteria in a science experiment, where x is the number of days after the start of the experiment. To the nearest whole number, how many bacteria will there be after 4 days? ________________________________________ Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 1 Name _______________________________________ Date __________________ Class __________________ 9. Does this set of ordered pairs satisfy an exponential function? Explain. 13. Which kind of model best describes the graph? {(2, 0.25), (1, 0.5), (0, 1.5), (1, 6)} ________________________________________ ________________________________________ ________________________________________ 10. The number of students at a university is 1320, and the number increases by 8% each year. Write an exponential function to model this situation. Then find about how many students there will be in 5 years. 14. Which kind of model best describes the data set? ________________________________________ 11. Bismuth-212 has a half-life of 60.5 minutes. Find the amount of bismuth-212 left from a 100-gram sample after 242 minutes. ________________________________________ 12. Determine which kind of model—linear, quadratic, exponential, or square-root— best describes this data set. {(2, 2), (1, 1), (0, 2), (1, 7), (2, 14)} X 1 2 3 4 Y 0.5 0.25 0 0.25 ________________________________________ 15. Emil has $500 in his savings account. He wants to save more money. He is looking at two investment plans. Under plan A, he will increase his account balance by $150 a year. Under plan B, he will increase his account balance by 25% each year. How much more will he save with Plan B after four years? Round your answer to the nearest whole. ________________________________________ 16. What is the average rate of change over the interval [1, 1]? Equation A X 1 0 1 2 Y 6 4 6 12 Equation B f ( x ) 2x 3 ________________________________________ Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 1 Name _______________________________________ Date __________________ Class __________________ Exponential Functions Answers 10. y 1320(1.08)t; 1940 Chapter Test Form B 1. B 2. G 3. D 4. F 5. B 6. F 7. B 8. G 9. B 10. G 11. C 12. G 13. C 14. G 15. A 16. G 17. D 18. H 19. C 20. H 11. 6.25 g 12. quadratic 13. exponential 14. linear 15. $121 16. A: 0, B: 2 1. 14, 7, 3.5 2. 2560 3. x y 3 2 9 2 2 3 1 2 0 6 1 18 2 54 3 162 4. 115 5. 0.25, 0.125, 0.0625 6. 1 4 7. 81 8. 1 ,1 16 9. no; as the x-values increase by a constant amount, the y-values are not multiplied by a constant amount. Original content Copyright © by Holt McDougal. Additions and changes to the original content are the responsibility of the instructor. Holt McDougal Algebra 1