Intermediate Algebra (11th edition)

CHAPTER 12 Review Exercises 709

REVIEW EXERCISES

CHAPTER 12

12.1 Write out the first four terms of each sequence.

1. 2. 3.

4. 5. 6.

Write each series as a sum of terms.

7. 
   
   
   
   8. 
      
      
      
      9. 
         
      
      
      
      
   
   
   
   

Evaluate each series.

10. 
    
    
    
    11. 
        
        
        
        12. 
            
        
        
        
        
    
    
    
    

13.Find the arithmetic mean, or average, of the total

retirement assets of Americans for the years

2004 through 2008 shown in the table. Round to

the nearest unit (in billions).

12.2–12.3 Decide whether each sequence is arithmetic, geometric,or neither.If the

sequence is arithmetic, find the common difference d. If it is geometric, find the common ratio r.

14.2, 5, 8, 11 15. 2, 6, 10 16. , , ,

17. 1, 1, 18.64, 32, 8, 19.64, 32, 16, 8

20.Concept Check Refer to the Chapter Opener on page 677.What is the eleventh term of

the Fibonacci sequence?

12.2 Determine the indicated term of each arithmetic sequence.

21. , ; 22. , ;

Determine the general term of each arithmetic sequence.

23. , 24.6, 3, 0,

Determine the number of terms in each arithmetic sequence.

25.7, 10, 13 , 49 26.5, 1,

Evaluate for each arithmetic sequence.

27. , 28.

12.3 Determine the general term for each geometric sequence.

29. 30. ,

2

15

,

2

75

,Á

2

3

- 1, -4, -16,Á

a 1 =- 2 d= 6 an=- 2 + 5 n

S 8

,Á -3,Á, - 79

a 1 =- 4 d=- 5 - 3,Á

a 1 =- 2 d= 5 a 16 a 6 = 12 a 8 = 18 a 25

,Á ,Á

1

2

- 1, -1, -1,Á

- ,Á

1

12

1

6

-

1

3

2

3

,Á -6, -2, ,Á

a

7

i= 4

i

a i+ 1

6

i= 1

a^2 i

4

i= 1

1 i+ 22

a

6

i= 3

a 15 i-^42

6

i= 1

a^1 i+^12

5

i= 1

i^2

an= a an= 1 n+ 121 n- 12 an=n 1 - 12 n-^1

1

2

b

n

an= an=n^2

n- 1

n

an= 2 n- 3

Year Assets (in billions of dollars)

2004 13,778

2005 14,862

2006 16,680

2007 17,916

2008 13,985

Source:Investment Company Institute.