@campbell_st what does "geometric" mean
Is the sequence geometric? 2, 6, 18, 54,...

Question

@campbell_st what does "geometric" mean 
Is the sequence geometric? 2, 6, 18, 54,...

campbell_st · Answer

geometric means that you multiply each term by the same number to get the next. 

in your sequence its

2, 2*3, 6*3, 18*3

so each term is multiplied by 3 to get the next.

agent0smith · Answer

You can find whether a sequence is geometric, by dividing a term by the term right before it.

2, 6, 18, 54

eg 6/2 = 3

18/6 = 3

54/18 = 3

so the sequence is geometric, since there is a common ratio of 3. If you divide a term by the one before it, and don't get the same ratio for all terms, then it's not geometric.

anonymous · Answer

so that would make it "yes"

agent0smith · Answer

Eg is this sequence geometric?

2, 8, 24, 48

8/2 = 4

24/8 = 3

48/24 = 2

the ratio is not the same, so it's not geometric.

anonymous · Answer

does it have to be mutilply? @campbell_st

agent0smith · Answer

Yes, it has to be the same multiple from one term to the next.

agent0smith · Answer

It can be multiplied by a fraction, though.

campbell_st · Answer

well dividing is the same as multiplying by a fraction 


100, 50, 25, 12.5       is dividing by 2   or multiplying by 1/2

anonymous · Answer

okay so it can be either of the two but it cant be add or minus right?

agent0smith · Answer

Adding or subtracting the same amount would make it an arithmetic sequence.

anonymous · Answer

o okay just making sure! thank you!

agent0smith · Answer

No prob, you're welcome.