suatu barisan geometri diketahui U3 = 27 U6= 1tentukan suku ke 8

U3 = a r² = 27
U6 = a r⁵ = 1
maka
a r⁵ = 1
a r² r³ = 1
27 r³ = 1
r³ = 1/27
r = 1/3

U8
= a r⁷
= a r⁵ r²
= 1 . (1/3)²
= 1/9