Задача №11900

Дано $5{\sin }^2\alpha +13{\cos }^2\alpha =6$$5{\sin }^2\alpha +13{\cos }^2\alpha =6$$$5{\sin }^2\alpha +13{\cos }^2\alpha =6$$. Найдите ${\mathrm{tg}}^2\alpha$${\mathrm{tg}}^2\alpha$$${\mathrm{tg}}^2\alpha$$.