" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2024 KUDO.TIPS - All rights reserved.
a = 9
U2 + U3 = 10
S∞ = ___ ?
U2 + U3 = 10
ar + ar^2 = 10
9r + 9r^2 = 10
9r^2 + 9r - 10 = 0
(3r - 2) (3r + 5) = 0
r = 2/3 atau r = - 5/3 [TM]
S∞ = a / (1 - r)
S∞ = 9 / (1 - (2/3))
S∞ = 9 / (1/3)
S∞ = 27 ← jawaban
Jumlah tak hingga deret tersebut 27.
catatan
Deret geometri tak hingga mempunyai jumlah , jika konvergen
Syarat konvergen
|r| < 1 atau -1 < r < 1