hitunglah U10,jika diketahui barisan 256,128,64

U1 = 256
r = 128/256 = ½

U10 = 256 x (½)^9 = 2^8-9 = ½

diket:
a=256
r=1/2
dit: U10?
jawab
Un= ar^n-1
U10=256x(1/2)^10-1
=256x(1/2)^9
=256x1/512
=256/512
=1/2