Find the Finite element solution for a equation:
(∂^2 u)/〖∂x〗^(2 ) +(∂^2 u)/〖∂y〗^2 +λu-c=0
using linear triangular finite elememts.
In the above equation u is scalar,λ is a constant and is a body force term(constant).

The boundary conditons are in terms of prescribed values of the function u or zero flux.