Question

Determine whether each sequence is a geometric sequence. If yes, then state the common ratio.

1, -4, 16, -64, ...

Answer 1

-4 is multiplied each time

1x-4= -4
-4x-4= 16
16x-4= -64

Answer 2

This is a geometric sequence with a common ratio of -4

Explanation:

Take the second term and divide by the first term

-4/1 = -4

Take the third term and divide by the second term

16/-4 = -4

Take the fourth term and divide by the third

-64/16 = -4

This is a geometric sequence with a common ratio of -4