Question

Diketahui suatu barisan geometri dgn u3 = 1per 3. u6 = 9. suku ke 9?

Answer 1

U3=ar^2= 1/3
u6=ar^5= 9

r^3= 9/ (1/3)= 27
r= 3

ar^2 = 1/3
a x 9 = 1/3
a= 1/3 x 1/9 = 1/27

u9 = ar^8= 1/27 x 3^8=6.561/27=243