Respostas

2014-04-23T22:48:16-03:00
A1 = 64
an = 1/128
r = 32/64 = 1/2
termo geral : an = a1.r^(n-1) ( "^" significa "elevado a" )
1/128 = 64 . 1/2^(n-1)
veja que 128 = 2^7 e 64 = 2^6
1/2^(n-1) = 1/(128 . 64)
1/2^(n-1) = 1/2^13
portanto
n-1 = 13 ==> n = 14 termos (resp)