Question

fie progresia geometrica in care b1=2 si b2=6 . Calculati b6

Answer 1

$\displaystyle b_1=2 \\ b_2=6 \\ b_6=? \\ q= \frac{b_2}{b_1} = \frac{6}{2} =3 \\ b_6=b_1 \cdot q^{n-1}=b_1 \cdot q^{6-1}=b_1 \cdot q^5=2 \cdot 3^5=2 \cdot 243=486$