Question

Calcule a soma dos 10 primeiros termos da pg (1024,512,256)

Answer 1

q = 256/512 = 1/2

an = a1.q^(n-1)

a11 = (512).(1/2)^(10)

a11 = 1/2

Sn = a1.[q^n - 1]/[q - 1]

S10 = (512).[(1/2)^10 - 1]/[1/2 - 1]

S10 = (512).[1/1024 - 1]/[-1/2]

S10 = (512).[-1023/1024]/[-1/2]

S10 = (-1024)[-1023/1024]

S10 = 1023