Answer:
Step-by-step explanation:
Let “a” be the first term and ”r” the common ratio of the GP. Then,
f(n) = ar^(n - 1).
f(2) + f(3) = 6f(4). (given)
ar + ar^2 = 6ar^3, or
1 + r = 6r^2, or
6r^2 - r - 1 = 0,
(3r + 1)(2r - 1) = 0.
r = -1/3, or 1/2.
If the common ratio is positive and the second term is 8 we have,
ar = 8, or
a*1/2 = 8, or a = 16.
f(n) = 16*(1/2)^(n - 1) = 2^4*2^(1 - n), or
f(n) = 2^(5 - n).
The first six terms of the GP are : 16, 8, 4, 2, 1, 1/2,…
××××××××××
Checking : f(2) + f(3) = 6f(4), (given).
LHS = 8 + 4 = 12.
RHS = 6* 2 = 12.
LHS = RHS.
