Question

Find an equation for the nth term of a geometric sequence where the second and fifth terms are -2 and 16, respectively.

Answer 1

i think it's an = 1 • (-2)n + 1

Answer 2

for a geometric series, we have
\[a_n=a_0\cdot r^{n-1}\\
a_3=-2=a_0r\\
a_5=16=a_0 r^4
\]
find out "r" first, then get the "\(a_0\)" and find the required term

Answer 3

is it an = 1 • 2n

Answer 4

is what \(1\cdot 2n\)
?

Answer 5

yes 1 x 2^n

Answer 6

the equation that you first wrote does not belong to "arithmatic" nor "geometric" sequence.

Answer 7

ahhhh im confused

Answer 8

did you understand the above formulae?

Answer 9

a little i tried it again and got an = 1 • (-2)^n - 1

Answer 10

is this right @electrokid