# Given that the third term #a_3# of a geometric sequence is #2# and the sixth term #a_6# is #128#, which term is #1/2# ?

##### 1 Answer

Jul 26, 2016

#### Answer:

#### Explanation:

We can write the general term of a geometric sequence as:

#a_n = ar^(n-1)#

where

In our example

#r^3 = (ar^5)/(ar^2) = a_6/a_3 = 128/2 = 64 = 4^3#

So the only possible Real value of

Note that

So