Question

Tentukan perbandingan (r) antar suku berurutan dan suku ke-6 dari barisan geometri berikut
a. 2,6,18,64...
b. 4,2, 1/2, 1/4,....
c. 1/3, 1/6, 1/12, 1/24

Answer 1

A) 2, 6, 18, 54, ...

r = U2 / U1
r = 6 / 2
r = 3

a = U1 => a = 2

Un = ar^n - 1
U6 = 2 × 3^5
U6 = 2 × 243
U6 = 486

b) 4, 2, 1/2, 1/4, ...

r = 2/4
r = 1/2

a = 4

U6 = 4 × (1/2)^5
U6 = 4 × 1/32
U6 = 1/8

c) 1/3, 1/6, 1/12, 1/24, ...

r = 1/6 / 1/3
r = 1/6 × 3
r = 1/2

a = 1/3

U6 = 1/3 × (1/2)^5
U6 = 1/3 × 1/32
U6 = 1/96

Semoga membantu ^_^