Let $$A = \left\{ (x, y) \in \mathbb{R}^2 : y \geq x^2 +c, \, c \in \mathbb{R} \right\}$$ Find the polar set for $A$.
My attempts: $(u, v) \in \mathbb{R}^2; l(x, y) := ux+vy, \partial A: t \rightarrow (x(t), y(t)) = ( ct, \sqrt{c}t).$ I'm trying to find max of $f(t) = l(x(t), y(t)) = uct+v\sqrt{c}t$. But it is $\infty$. Help me please!