Question

Determine o termo geral da seguinte sequência
( 3, 9, 27, 81 )

Answer 1

$(a_1,a_2,a_3,a_4,\dots)=(3,9,27,81,\dots)\\\\ \boxed{a_n=a_kq^{n-k}}\ \therefore\ a_2=a_1q\ \therefore\ q=\dfrac{9}{3}\ \therefore\ q=3\\\\ a_n=a_1q^{n-1}\ \therefore\ a_n=3(3^{n-1})=3^{1+n-1}\ \therefore\\\\ \boxed{a_n=3^n}$