15. Let a1 = 3/4 and an+1 = (-1/2)an for n = 1,2,… What is

|
A. (1 + 27)/22 |
B. –(2 + 28) |
C. –((1 + 27)/211) |
|
D. (1 + 27)/28 |
E. (26 – 1)/211 |
Solution: The answer is C
Note: This is a time waster. The only reason I can see for using it is to see if the examinee has enough mathematical sense to skip it and come back to it at the end, time permitting.(rjm)
List a few iterations starting with a1 to find the formula for an as follows:


So that,


