Question

DADA A P.G (3,9,27,81,...),DETERMINE O 20ª TERMO.

Answer 1

q = 9 : 3 = 3
a1 = 3
n = 20
an = a20 = ?

an = a1 . $q^{n - 1}$
a20 = 3 . $3^{20 - 1}$
a20 = 3 . $3^{19}$
a20 = 3 . 1.162.261.467
a20 = 3.486.784.401

PA = ( 3, 9, 27, 81, 243, 729, 2.187, 6.561, 19.683, 59.049, 177.147, 531.441, 1.594.323, 4.782.969, 14.348.907, 43.046.721, 129.140.163, 387.420.489, 1.162.261.467, 3.486.784.401)

Answer 2

Resposta:

an = a1 .

a20 = 3 .

a20 = 3 .

a20 = 3 . 1.162.261.467

a20 = 3.486.784.401

Explicação passo a passo: