Local implicit function parameterization

Under the implicit function theorem hypotheses, the solution set is locally a graph
Local implicit function parameterization

Let F:URn+mRmF:U\subseteq\mathbb{R}^{n+m}\to\mathbb{R}^m be , and suppose (a,b)U(a,b)\in U satisfies F(a,b)=0F(a,b)=0 and det(Fy(a,b))0. \det\left(\frac{\partial F}{\partial y}(a,b)\right)\neq 0.

Corollary: There exist AA of aa and BB of bb and a C1C^1 function g:ABg:A\to B such that the solution set of F(x,y)=0F(x,y)=0 in A×BA\times B is exactly the graph of gg: {(x,y)A×B: F(x,y)=0}={(x,g(x)): xA}. \{(x,y)\in A\times B:\ F(x,y)=0\}=\{(x,g(x)):\ x\in A\}.

Connection to parent theorem: This is precisely the conclusion of the , viewed as a geometric parameterization statement.