SOLUTION: 11. https://answers.yahoo.com/question/index?qid=20210419165800AAUVXoP

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: 11. https://answers.yahoo.com/question/index?qid=20210419165800AAUVXoP      Log On


   



Question 1179195: 11.
https://answers.yahoo.com/question/index?qid=20210419165800AAUVXoP

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
describe the sequence as arithmetic, geometric, neither. For arithmetic and geometric sequences, give the common difference or common ratio.?
{ 3600, 1440, 576, 230, 4,...}
check if the sequence is arithmetic
3600-1440=2160
1440-576=864
difference is not same, so the sequence is not arithmetic
check if the sequence is geometric:
1440%2F3600=2%2F5
576%2F1440=2%2F5
ratio is same, so sequence highlight%28is%29 highlight%28geometric%29=>r=2%2F5
let’s find nth term formula
a%5Bn%5D=a%5B1%5D%2Ar%5E%28n-1%29.........plug in a%5B1%5D=3600 and r=2%2F5

a%5Bn%5D=3600%2A%282%2F5%29%5E%28n-1%29
let’ check third term:
a%5B3%5D=3600%2A%282%2F5%29%5E%283-1%29
a%5B3%5D=3600%2A%282%2F5%29%5E2
a%5B3%5D=3600%2A%284%2F25%29
a%5B3%5D=576