Question

Which sequences are geometric? Select three options.

Answer 1

(i) –2.7, –9, –30, –100, ... case of a geometric sequence

(ii) –1, 2.5, –6.25, 15.625, ... case of a geometric sequence

(iii) 9.1, 9.2, 9.3, 9.4, ... not a case of a geometric sequence

(iv) 8, 0.8, 0.08, 0.008, ... case of a geometric sequence

(v) 4, –4, –12, –20, .. not a case of a geometric sequence

What is a geometric sequence?

A geometric sequence is one in which the ratio of two succeeding terms is fixed. The common ratio is what's known as this ratio.

Checking each sequence one by one right now.

(i) –2.7, –9, –30, –100, ...

r=(-9/2.7)=3.33

=(-30/9)=3.33

=(-100/9)=3.33

⇒This is a case of a geometric sequence

(ii) –1, 2.5, –6.25, 15.625, ...

r=(2.5/-1)=2.5

=(-6.25/2.5)=2.5

=(15.625/-6.25)= 2.5

⇒This is a case of a geometric sequence

(iii) 9.1, 9.2, 9.3, 9.4, ...

since the ratio between terms is not the same.

⇒This is not a case of a geometric sequence

(iv) 8, 0.8, 0.08, 0.008, ...

since the ratio between terms is the same.

⇒This is a case of a geometric sequence

(v) 4, –4, –12, –20, ..

since the ratio between terms is not the same.

⇒This is not a case of a geometric sequence

To learn more about geometric sequence visit:

brainly.com/question/24643676

#SPJ1