Consider the following program \begin{align} \max_{x,y \geq 0} f(x,y)\tag{1} \end{align}
I wanna construct a solution with $y^* = 0$ and $x^* > 0$. Suppose FOCs satisfy \begin{align} f_x(x^*,y^*) = 0\\ f_y(x^*,y^*) < 0 \end{align}
and SOCs also satisfy \begin{align} f_{xx}(x^*,y^*) < 0 \quad \text{and} \quad \det(H(f)(x^*,y^*)) > 0 \end{align}
where $H(\cdot)$ is the hessian.
- Is $(x^*,y^*)$ a solution of $(1)$?