Question
A certain 300-term geometric sequence has first term 1337 and common ratio -1/2. How many terms of this sequence are greater than 1?
Answers
Steve
1337 * (-1/2)^n <= 1
Since
2^10 = 1024
2^11 = 2048
|Tn|>1 for n<=11
But, Tn < 0 for n even, so only T1,3,5,7,9,11 are greater than 1. So, just 6 terms.
Since
2^10 = 1024
2^11 = 2048
|Tn|>1 for n<=11
But, Tn < 0 for n even, so only T1,3,5,7,9,11 are greater than 1. So, just 6 terms.
Anonymous
6 is correct