Question

help please i want to know if my reasoning is correct - which are geometric sequences ?

Answer 1

would the answers be A B and D - because C would be arithmetic sequence due to the addition of 2

Answer 2

@phi Hi sorry to bother but i was wondering if my reasoning is correct?

Answer 3

yes, you've got the idea.

Answer 4

yay! thank you aww geometric chapter is killing me hahaha @phi

Answer 5

except in C, you are adding +3 not +2

Answer 6

ohhhhh okkk n_n

Answer 7

the way people check is take any pair of the sequence. Example, in the first series
1,3,9

look at the pair 1,3
divide 3/1 = 3

then look at another pair. example 3,9 and divide 9/3 = 3
if you keep getting the same answer, it is geometric.

or, if it's obvious, just notice that 3 (in this example) times a term gives the following term.

Answer 8

ohhhh ok i remembered that a2/a1 to get the ratio

Answer 9

yes, that is what people teach. that ratio is what you multiply each term by to get the next term.

Answer 10

ok thank you n_n ! @phi awwww i really wished we had tutors or teachers like you guys explaining things thoroughly

Answer 11

yw