Question

A soma dos 10 primeiros termos da P.G. (1; 1/2; 1/4; ...)

Answer 1

a1 = 1
a2 = 1/2
a3 = 1/4
q = 1/2 : 1/1  = 1/2 * 1/1 = 1/2 ****
an = a18 q^n-1
an = 1 * (1/2)^n-1
n = 10 
a10 = 1 * ( 1/2)^9
a10 = 1 * 1/512 =  1/512

S10 = a1 ( q^10    - 1 ) / ( q - 1)
S10 =  1(  1/2^10  - 1) / ( 1/2 - 1 )
S10 = ( 1/1024  - 1/1 ) / ( -1/2)
S10 = ( - 1023/1024 ) /( - 1/2)
S10 = -1023/1024 * -2/1 = 2046/1024 =1023/512