Question

Jumlah deret: 1/2+1+2+4+...+256, adalah....

Answer 1

A = 1/2
r = 1/(1/2) = 2
Un = 256
ar^(n - 1) = 256
(1/2)2^(n - 1) = 2^8
(1/4)2^n = 2^8
2^n = 2^10
n = 10

S10 = a(r^10 - 1)/(r - 1)
= (1/2)(2^10 - 1)/(2 - 1)
= (1/2)(1023)
= 1023/2