Question

Which of the following sequences are not geometric? (check all that apply) a. 2,10,50,250,1250 b. 1,4,9,16,25,36 c. -4,-2,-1,-0.5,-0.25,-0.125 d. 1,1,2,3,5,8,13,21

Answer 1

A is geometric because each number is multiplied by 5.

B is not geometric because it is an arithmetic sequence. 

C is a geometric sequence because each number is divided by 2.

D is neither geometric not arithmetic because there is no common ratio and there is not a pattern being added or subtracted to each number.

So, your answer should be B and D.

Answer 2

The sequences 2, 10, 50, 250, 1250 and -4, -2, -1, -0.5, -0.25, -0.125 are the geometric sequences.

What is geometric sequence?

Geometric sequence is a type of sequence where each succeeding term is produced by multiplying each preceding term by a fixed number.

According to the given question.

We have some sequences.

If we take

First sequence

2, 10, 50, 250, 1250

Since,

$\frac{10}{2} = \frac{50}{10} = 5$

For the above sequence, the common ratio is five. Hence, the sequence 2, 10, 50, 250, 1250 is a geometric sequence.

Second sequence

1, 4, 9, 16, 25, 36

Since,

$\frac{4}{1} \neq \frac{9}{4}$

For the second sequence, there is no any common difference. Hence, the second sequence 1, 4, 9, 16, 25, 36 is not a geometric sequence.

Third sequence

-4, -2, -1, -0.5, -0.25, -0.125

Since,

$\frac{-2}{-4} =\frac{-1}{-2}=0.5$

similarly, $\frac{-0.5}{-1} =\frac{-0.25}{-0.5} =0.5$

For the third sequence, the common ration is 0.5. Hence the given sequence, -4, -2, -1, -0.5, -0.25, -0.125 is a geometric sequence.

Fourth sequence

1, 1, 2, 3, 5, 8, 13, 21

$\frac{1}{1} \neq \frac{2}{1}$

For the fourth sequence, there is no any common ratio. Therefore, the given sequence is not a geometric sequence.

Hence, the sequences 2, 10, 50, 250, 1250 and -4, -2, -1, -0.5, -0.25, -0.125 are the geometric sequences.

Find out more information about geometric sequences here:

https://brainly.com/question/11266123

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