Question

Deret geometri
r= 1/2
a = 8
berikut deretnya, 8+4+2+.....+U10

Ditanya S10?

Answer 1

Diketahui :
r = 1/2
a = 8

maka :
Sn = (a(1 - rⁿ)) : (1 - r)
S10 = (8(1 - (1/2)¹⁰)) : (1 - 1/2)
S10 = (8(1 - 1/1024)) : (1/2)
S10 = (8(1024/1024 - 1/1024)) x 2
S10 = (8(1023/1024)) x 2
S10 = (1023/128) x 2
S10 = 1023/64
S10 = 15 63/64
S10 = 15,89