Question

A geometric sequence has a term of a4 = –54 and a common ratio of r = 3. What is the rule for the nth term?

Answer 1

see 4th term and common ratio is given so u can find the first term..and after that u can directly apply the formula to find the n th term

Answer 2

So i could put -54/3 in a calculator and then what?

Answer 3

an=-2*-18^n-1

Answer 4

did u find the first term???

Answer 5

would that work?

Answer 6

no it won't...whats -18???

Answer 7

is -18 involved in any way to this problem? lol

Answer 8

no its not...

Answer 9

ok what about this one

Answer 10

an=9*3^n-1

Answer 11

not all all...did u find first term??? and whats 9??

Answer 12

ok, to find the first term, what would i need to do

Answer 13

-54 = a*(3)^(4-1).....a--- first term... 3-- common ratio...

Answer 14

Ok i get that part