Question

Determine whether each sequence is arithmetic geometric or neither if the sequence is arithmetic give the common difference if geometric give the common ratio 1. 6,18,54,162, 2. 4,10,16,22 3. 1,1,2,3,5,8 4. 625,125,25,5 5. 5,8,13,21,34

Answer 1

1.

6 , 18 , 54 , 162

Geometric sequence. Common ratio 3

2.

4 , 10 , 16 , 22

Arithmetic sequence. Common difference 6

3.

1 ,1 , 2 , 3 , 5 , 8

Neither, Fibonacci sequence:

1 + 1 = 2 , 1 + 2 = 3 , 2 + 3 = 5 , 3 + 5 = 8

4.

625 , 125 , 25 , 5

Geometric sequence. Common ratio 1 / 5

5.

5 , 8 , 13 , 21 , 34

Neither, Fibonacci sequence:

5 + 8 = 13 , 8 + 13 = 21 , 13 + 21 = 34

Answer 2

arithmetic sequence, a geometric sequence, or neither. 1, 2, -1, 3, -2, ...