Question

Calcule o número de termos de uma PG finita em que a1 = 2 Q = 3 e s = 6560

Answer 1

$> \: resolucao \\ \\ \geqslant \: progressao \: \: geometrica \\ \\ sn = \frac{a1(q {}^{n} - 1)}{q - 1} \\ \\ 6560 = \frac{2(3 {}^{n} - 1)}{3 - 1} \\ \\ 6560 = \frac{2(3 {}^{n} - 1)}{2} \\ \\ 6560 = 3 {}^{n} - 1 \\ \\ 6560 + 1 = 3 {}^{n} \\ \\ 6561 = 3 {}^{n} \\ \\ 3 {}^{8} = 3 {}^{n} \\ \\ n = 8 \\ \\ \\ resposta \: > \: pg \: de \: 8 \: termos \\ \\ \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \geqslant \geqslant$