Question

5. Carilah enam suku pertama dari barisan geometri berikut
a. a = 2; r =1/2
b. a = 12; r =1/3

Answer 1

Verified answer

5a) Un = ar^n-1
U1 = a = 2
U2 = ar = 2 • ½ = 1
U3 = ar² = 2 • ( ½ )² = 2 • ¼ = ½
U4 = ar³ = 2 • ( ½ )³ = 2 • 1/8 = ¼
U5 = ar⁴ = 2 • ( ½ )⁴ = 2 • 1/16 = 1/8
U6 = ar^5 = 2 • ( ½ )^5 = 2 • 1/32 = 1/16
barisanya 2 , 1 , ½ , ¼ , 1/8 , 1/16

b) U1 = a = 12
U2 = ar = 12 • ⅓ = 4
U3 = ar² = 12 • ( ⅓ )² = 12 • 1/9 = 12/9 = 4/3
U4 = ar³ = 12 • ( ⅓ )³ = 12 • 1/27 = 12/27 = 4/9
U5 = ar⁴ = 12 • ( ⅓ )⁴ = 12 • 1/81 = 12/81 = 4/27
U6 = ar^5 = 12 • ( ⅓ )^5 = 12 • 1/243 = 12/243 = 4/81
barisanya = 12 , 4 , 4/3 , 4/9 , 4/27 , 4/81