Question

Suku pertama barisan geometri =36 dan rasionya =1/3, maka nilai 4erupakan suku ke.......
A. 5. B. 4. C. 3. D. 2

Answer 1

A = 36
r = ⅓
Un = a * r^(n-1)
4 = 36 * ⅓^(n-1)
1/9 = ⅓^(n-1)
n-1 = 2
n = 3

jawaban: C
semoga membantu :)

Answer 2

Un = 4
ar^(n - 1) = 4
36(1/3)^(n - 1) = 4
(1/3)^(n - 1) = 4/36
(1/3)^(n - 1) = 1/9
(1/3)^(n - 1) = (1/3)^2
n - 1 = 2
n = 3

Atau
36, 9, 4, 4/3, 4/9, 4/27, ....
Jadi 4 adalah suku ke 3