Question

determine o numero de termos da PG 1,2...256

Answer 1

a1 = 1
a2 = 2
an = 256

q = a2/a1 = 2/1
q = 2

               n - 1
an = a1. q

                n - 1
256 = 1.2

             n - 1
256 = 2

   8       n - 1
2    = 2

8 = n - 1
8 + 1 = n
9 = n
n = 9

Resp.: 9 termos

PG: (1,2,4,8,16,32,64,128,256)