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

Can you please show me the basic geometric function?

Answer 2

Im honestly so lost with this one

Answer 3

see the fith term is given and the second term is given then we can find the common ratio..

Answer 4

to know a geometric sequence we need to know the first term and the common ratio
so if a be the first term and r be the common ratio
then the nth term of the geometric sequence is given by a* r^(n-1)

Answer 5

thus second term is given by
ar= -2
and the fifth term is
given by
ar^4 = 16

Answer 6

so using the above eq. we need to know a and r here first..

Answer 7

thus ar^4 /ar =16/-2
or
r^3= -8 =(-2)^3
hence r=-2
now ar =-2
so a= 1

Answer 8

do i start putting it into the fromula

Answer 9

yup as u wish..

thus nth term is given by = 1 *(-2)^(n-1)...

Answer 10

Thank you so much!