(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
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