Question

Determine o número de termos da PG (-1,-2,-4,...,-512

Answer 1

Resposta:

a1 = -1

q = a2/a1

q = -2/-1

q = 2

an = -512

an=a1.q^(n-1)

-512=-1.2(n-1)

-512/-1=2^(n-1)

512=2^(n-1)

2^9=2^(n-1)

corta as bases 2

9=n-1

n=9+1

n=10 termoss