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

@Loser66

Answer 2

@amistre64 @hartnn

Answer 3

nth term = a1* r^(n-1)
so 5th term = a1*r^4
and 2nd term = a1*r

this should help

r = common ratio which is the value you multiply each term to get the next term

Answer 4

Is it an = 1 * (-2)^n-1?

Answer 5

r^3 = 16 / -2 = -8

so r = -2

Answer 6

so a1 = -2/-2 = 1

Answer 7

a1 must = 1,
r = -2
then 1*(-2)^n-1, thanks man!

Answer 8

you r right

Answer 9

yw - actually i'm a woman

Answer 10

Oh lol ok, won't happen again :)

Answer 11

maybe a write like a man! - that's ok

Answer 12

Nononono! I wasnt saying that lol!! The internet is tricky sometimes! :P