Question

Fie progresia geometrica in care b1=2,b2=6.calculati b5

Answer 1

Progresia geometrica are ratia notata cu q.
b1= 2 => b2= 2*q=6 => q=3
b3=b2*q= 6*3=18
b4=b3*q=18 *3=54
b5=b4*q=54*3=162
Raspuns : b5=162

Answer 2

b1= 2
b2= 6
b5=?
Progresie geometrica
Aflam q:
$b_{2}= b_{1}*q\ \textless \ =\ \textgreater \ q= \frac{b_{2}}{b_{1}} = \frac{6}{2} =3 =\ \textgreater \ q=3$
[tex]b_{5}= b_{1}*q^4=\ \textgreater \ b_{5}=b_{1}*3^{4}=\ \textgreater \ b_{5}=2*81=162 ; b_{5}=162[/tex]