Question

What is the common ratio of the geometric sequence below?

–2, 4, –8, 16, –32

Answer 1

-2 times -2  will give you 4 or (-2 x -2=4)

-8 times -2 will give you 16 or (-8 x -2=16)

16 times -2 will give you -32 or (16 x -2=-32)

Answer 2

Answer:

The common ratio of the given sequence is -2.

Step-by-step explanation:

Given : The geometric sequence  –2, 4, –8, 16, –32

To find : The common ratio of the given sequence ?

Solution :

Geometric series is in the form $a,ar,ar^2,ar^3....$

Where, a is the first term and r is the common ratio.

The formula of common ratio is dividing second term with the first one.

$r=\frac{a_2}{a_1}$

In the given sequence, –2, 4, –8, 16, –32

First term is $a_1=-2$

Second term is $a_2=4$

$r=\frac{a_2}{a_1}$

$r=\frac{4}{-2}$

$r=-2$

Therefore, The common ratio of the given sequence is -2.