Section 1 Quiz #2 Key

advertisement
Quiz #2
Sequences and Series
Name: Key
Show enough work that I can reproduce your results.
Calculators are okay, but show evidence that you are actually doing the problems and not just typing
them into your calculator.
1.
Write each series in  notation:
a. 5  2  9  16 
13
 79   (7 k  12)
k 1

8 11 14 17
b. 5   
 
3 9 27 81

k 1
(1)k  3k  2
3k 1
3
k
3
1
Evaluate the infinite sum:  3    5 
1 4
k 1  5 
1
5

2.
3.
Evaluate the sum:
 1
 1 1 1 1 1 1  1 1 
1



         
2(k  2)   2 6   4 8   6 10   8 12 
k 1  2k
100
1 1
1
1
 

2 4 202 204
3
1
1
 

4 202 204

1   1
1 
 1





 198 202   200 204 
4. If an  4n  1 , then an 
6
 3,7,11,15,19,23
n1
Sn 6n1  3,10,21,36,55,78
Sn is the sequence of partial sums of an .
5. If an  4n  1 , then
6. Write an explicit formula for Sn , in #4 above.
Sn  3  7  11 
n
 first  last  
2
n
  3  (4n  1) 
2
n
  4n  2 
2
 (4n  1) 
Download