Mathematics - Continuity - Differentiability Question with Solution | TestHub

Elimination gives $y^2-x^2=4$. Thus $y{y}^{\prime }=x$ and $y{y}^{\prime \prime }+(y\prime {)}^2=1$. Multiplying by $y^2$ gives $y^3{y}^{\prime \prime }=y^2-x^2=4$.