MathGloss

Let DR2D\subset\mathbb R^2 be connected and open and let f:DRf:D\to \mathbb R be of class C2C^2. Then the Laplacian of ff is given by the sums of the second partial derivatives Δf(z)=fxx(z)+fyy(z).\Delta f(z) = f_{xx}(z) + f_{yy}(z).

Wikidata ID: Q203484