Step-by-step explanation:
#1
a. -6, -9, 12
- There is no sequence since the difference between the terms is not common and the ratio of the terms is not common
b. t(n) = 0.5 - 6
- There is no sequence as all the terms are same regardless the value of n
c. 32, 16, 8
- The sequence is geometric as common ratio is 1/2, each next term is half the previous one
#2
a. 8, 16, 32, 64, ...
- This is a geometric sequence as the common ratio is 2
b. 1, 1, 2, 3, 5, 8, ...
- This is neither one since no common difference or ratio between the consecutive terms
c. 5, 5, 5, ...
- This is neither one since common difference is zero or common ratio is 1
d. -101, -99, -97, -95, ...
- This is a arithmetic sequence since the common ratio is 2
#3
According to question the sequence is:
- 200000, 100000, 50000, ...
We see each number is half the previous one so this is a GP with common ratio of 1/2
