Question

Suku ke-n deret geometri adalah Un.Jika diketahui U6/U8=3 dan U8.U2=1/3 ,maka nilai U10=........

Answer 1

U6/U8 = ar^5/ar^7 = 3
r^2 = 1/3
r= √1/3

U8 x U2 = ar^7 x ar = 1/3
a^2 r^8 =1/3
a^2 (r^2)^4 = 1/3
a^2 (1/3)^4 =1/3
a^2 = 27
a= 3√3

u10 = ar^9 = 1/27