barisan geometri jika U3=2 U7=32 MAKA U9=?

U3 = a.r² = 2 ...(1)
U7 = a.r⁶ = 32 ...(2)

a.r⁶ = 32
a.r² . r⁴ = 32
 2  .  r⁴ = 32
r⁴ = 16
r  = 2

a.r² = 2
a.2²=2
a .4= 2
a= ¹/₂

U9 = a.r⁸
U9 = ¹/₂ . 2⁸
U9 = ¹/₂ . 256
u9 = 128

Un=ar^n-1
U3=ar^2=2
U7=ar^6=32
a=2/r^2 (1)
a=32/r^6 (2)
a(1)=a(2) = 2/r^2 = 32/r^6 = r^6/r^2 = 32/2
= r^6-2 = 16 > r^4 = 16 MAKA r = 2(akar4 dari 16)
a=2/2^2= 2/4 = 1/2 / a=32/r^6 = 32/64 = 1/2
U9=1/2r^8 = 1/2 x 256 = 128