---

\(\alpha+\beta=-\cfrac{8}{3}\) এবং \(\alpha \beta=\cfrac{2}{3}\)
\(\therefore \cfrac{1}{\alpha^2}+\cfrac{1}{\beta^2}=\cfrac{\beta^2+\alpha^2}{\alpha^2\beta^2}\)
\(=\cfrac{(\alpha+\beta)^2-2\alpha\beta}{(\alpha\beta)^2}\)
\(=\cfrac{(-\cfrac{8}{3})^2-2\times \cfrac{2}{3}}{(\cfrac{2}{3})^2}\)
\(=\cfrac{\cfrac{64}{9}-\cfrac{4}{3}}{\cfrac{4}{9}}\)
\(=\cfrac{\cfrac{64-12}{9}}{\cfrac{4}{9}}\)
\(=\cfrac{52}{9}\times \cfrac{9}{4}=13\)