which is identical to the result for daily compounding. Therefore, replacing a
differential time interval dt by a finite time interval of t 1 day gave the
same result, which leads us into believing that reasonably accurate results can
be obtained by replacing differential quantities by sufficiently small differences.
Next, we develop the finite difference formulation of heat conduction
problems by replacing the derivatives in the differential equations by differences.
In the following section we will do it using the energy balance method,
which does not require any knowledge of differential equations.