Question

Given an example of an elliptic partial differential equation of 2nd order,

justifying your answer

Answer 1

The Laplace's equation is the example of an elliptic partial differential equation of 2nd order

$$\nabla^2\phi(x,y,z)=\frac{\partial^2\phi}{\partial x^2}+\frac{\partial^2\phi}{\partial y^2}+\frac{\partial^2\phi}{\partial z^2}=0$$