Question

Teman bantuin yaa pliss :) + caranya
dik: barisan geometri tak hingga dengan U2 = 30 dan U4= 375/32. jumlah deret tak hingga tersebut adalah?

Answer 1

U2 = ar = 30
u4 = ar³ = 375/32
ar³/ar = (375/32)/30
r² = 25/64
r = 5/8

ar = 30
5/8 a = 30
a = 48

sn = a/(1-r)
     = 48/(1-5/8)
     = 48/(3/8)
     = 128

Answer 2

U2=ar
u4=ar^3

u4/u2 = ar^3/ar
(375/32)/30 = r^2
r^2 = 375/960
r = akar (375/960)
r = 5/8

u2 = 30
ar = 30
a = 30/r
a = 30/(5/8)
a = 48

s tak hingga = a/(1-r)
= 48/(1 - 5/8)
= 48/(3/8)
= 128

dicek ya mgkin ada salah