Which of the following are examples of a geometric sequence? select any and all that apply: may be more than one correct answer.
( 1 , 1/2 , 1/6 , 1/24 , 1/120 , )
( 1 , -2 , 3 , -4 , 5 , )
( 1 , -2 , 4 , -8 , 16 , )
( 0 , 1 , 0 , -1 , 0 , )
( 9 , 3 , 1 , 1/3 , 1/9 , )
( 1 , 3 , 5 , 7 , 9 , )

( 1 , -2 , 4 , -8 , 16 , ... )

( 9 , 3 , 1 , 1/3 , 1/9 , ... )

Step-by-step explanation:

A geometric sequence has a common ratio in consecutive terms,

In sequence,

i.e.

is not a Geometric sequence,

1 , -2 , 3 , -4 , 5 , ...

i.e. 1 , -2 , 3 , -4 , 5 , ... is not a Geometric sequence,

In sequence,

1 , -2 , 4 , -8 , 16 , ...

i.e. 1 , -2 , 4 , -8 , 16 , .... is a Geometric sequence,

In sequence,

0 , 1 , 0 , -1 , 0 , .....

i.e. 0 , 1 , 0 , -1 , 0 , .....is not a Geometric sequence,

In sequence,

9 , 3 , 1 , 1/3 , 1/9 , ...

i.e.  9 , 3 , 1 , 1/3 , 1/9 , ... is a Geometric sequence,

In sequence,

1 , 3 , 5 , 7 , 9 , ...

i.e. 1 , 3 , 5 , 7 , 9 , ... is not a Geometric sequence

a

step-by-step explanation:

the answer is a