Question

1. Tentukanlah suku ke-n dari barisan geometri berikut!
A. 12, 6, 3, 1 1/2,... jika n = 6

C. 1/4 , 1/2, 1 , 2,... jika n = 10

e. 1, 1/3, 1/9 , 1/27,... jika n = 8

Answer 1

Baris dan deret geometri

Answer 2

(A) r = U2/U1 = 6/2 = 1/2
U6 = ar^5 = 12 . 1/2^5
= 12 . 1/32
= 3/8
(C) r = U2/U1 =1/2 : 1/4 = 2
U10 = ar^9 = 1/4 . 2^9
= 1/4 . 512
= 128
(E) r = U2/U1 = 1/3 : 1 = 1/3
U8= ar^7 = 1 . 1/3^7
= 1/2187