Step-by-step answer:
Given:
Geometric sequence with
second term, T2 = 6
third term, T3 = 12
Wants to have the explicit and recursive rules.
Solution:
common ratio, r = 12/6 = 2
Therefore the first term, T1
= second term /r
= 6/2
=3
Thus the absolute rule is
Tn = T1 *r^(n-1) where T1 = 3, r=2. Check: T3 = T1*2^(3-1) = 3*2^2=12 ...good
The recursive rule (depending on the previous term)
Tn = Tn-1*r = 2*Tn-1