I have a question regarding the discretization of the wave equation.
Consider the wave equation in one dimension for a function
with the discretization ( and )
Now the "technical" question. It starts by adding, to the right hand side of the discrete version, a function :
Such that when I choose I cancel the terms with time dependence . Doing that modifies the discretization of the 2nd time derivative, and the resulting discrete equation is not anymore a "genuine" wave equation. But then, how would the differential form of the last equation look like?
Any help would be highly appreciated!! Thanxxxxxxxxx!