Question

quantos termos tem a p.g ( 243, 81, 27, ...1)
310

Answer 1

an = a1 . q ^n - 1
1 = 243 . (1/3) ^ n - 1
1/243 = (1/3) ^ n - 1
(1/3)^5 = (1/3) ^ n -1
então n - 1 = 5, logo n = 6 (ou seja, 6 termos)