Policzmy q:
[tex]a_9=a_6*q^3\\\frac{a_6}{a_9}=\frac{a_6}{a_6*q^3}=\frac{1}{q^3}\\\frac{1}{q^3}=2\sqrt2\ |*q^3\\1=2\sqrt2*q^3\ |:2\sqrt2\\q^3=\frac{1}{2\sqrt2}\\q^3=(\frac{1}{\sqrt2})^3\\q=\frac{1}{\sqrt2}*\frac{\sqrt2}{\sqrt2}=\frac{\sqrt2}{2}[/tex]
Policzmy 10-ty wyraz:
[tex]a_{10}=a_3*q^7\\a_{10}=8*(\frac{\sqrt2}{2})^7=8*\frac{8\sqrt2}{128}=\frac{64\sqrt2}{128}=\frac{\sqrt2}{2}[/tex]