Question Number 183447 by greougoury555 last updated on 26/Dec/22
$$\:\begin{cases}{{y}=\mathrm{sec}\:^{{n}} \theta−\mathrm{cos}\:^{{n}} \theta}\\{{x}=\mathrm{sec}\:\theta−\mathrm{cos}\:\theta}\end{cases} \\ $$$$\:{xy}\:'+\left({x}^{\mathrm{2}} +{y}^{\mathrm{2}} \right){y}''\:=? \\ $$