Q:

Plz help!There is a certain infinite geometric series whose first term and common ratio are both real numbers, each of whose terms is the cube of the first series’ terms, is 1. Obtain the common ratio of the first series.

Accepted Solution

A:
Answer:The common ratio of the first G.P. series will be the cube root of the common ratio of the second G.P. series.Step-by-step explanation:Let us assume that the first series has first term a and the common ratio r and  is given by  a, ar, ar², ar³, ......... up to infinite terms It is given that the terms of the second series are a cube of the corresponding terms of the first series. So, the second series is [tex]a^{3}, a^{3} r^{3} , a^{3} r^{6}, a^{3} r^{9}, ......[/tex] up to infinite terms. So, it is clear that the second series is a G.P. series with first term a³ and common ratio r³. Therefore, the common ratio of the first G.P. series will be the cube root of the common ratio of the second G.P. series. (Answer)