What is the relationship between the successive terms in this sequence: -3.2, 4.8,-7.2, 10.8,..?

1 Answer
Oct 19, 2017

Common ratio #r = -(3/2)#
#n^(th) term = a.r^(n-1)# where a is the first term.

Explanation:

Successive terms are multiplied by #-(3/2)# to arrive at the next term.

First term #a_1 = -3.2#
Second term #a_2 = 4.8 Common ratio **r** can be found by dividing the successive terms. #:.# common ratio #= (-4.8)/(3.2) = -(3/2)#

#n^(th) term = a.r^(n-1) = -(3.2)(-3/2)^(n-1)#
#5^(th) term = a.r^4 = -(3.2) * (-3/2)^4 = -16.2#