Question

Найдите шестой член геометрической прогрессии (
b_{n} ) если b_{1} =0,81 и q = - \frac{1}{3}

Answer 1

$b_{n}=b1* q^{n-1}$
$b_{6}=0,81* \frac{1}{3} ^{6-1}$
$b_{6}=0,81* \frac{1}{3} ^{5}$
$b_{6}=0,81* \frac{1}{243}$
$b_{6}=\frac{0,81}{243}$
$b_{6}=\frac{0,01}{3}$
$b_{6}= \frac{1}{300}$

Answer 2

b6=b1*q^5
b6=0.81*(1/3)^5=0.81/3^5=0.81/243=1/300