Question

Determine 6th term in the geometric sequence whose first term is 3 and whose common ratio is -4.

Answer 1

$a_1=3$
$a_2=-4a_1$
$a_3=-4a_2=(-4)^2a_1$
$\cdots$
$a_6=-4a_5=\cdots=(-4)^5a_1$

$\implies a_6=(-4)^5\cdot3=-3072$