Question

Find the 7th term of the sequence given r=8 and a1= -2

Answer 1

Wait, geometric sequence: an= a1 r^(n-1)

Answer 2

ok

Answer 3

Where r represents the common ratio between every number. So, if you think about it, if you multiply 8 to -2 you get -16
8*-2=-16
Notice that 6 is a2.
a2=-16
Then, -16*(8)=-128
a3=-128
and you could do this until you get to a7. But, I'm sure you notice that method is tedious.
So, applying the nth term of a geometric sequence: an=a1r^(n-1)
a7= -2(8)^(7-1)
a7=-2(8)^6
a7=-524288

Answer 4

I hope that helps. It's also helpful to know that a geometric sequence is defined as: A sequence whose consecutive terms have a common ratio.
\[\frac{ a2 }{ a1 }=r, \frac{ a3 }{a2 }=r, \frac{ a4 }{ a3 }=r... \]
r is the common ratio

Answer 5

oh i got it. thx bro