An unsteady state heat conduction problem is given by $\frac{\text{d}\text{e}\text{l}\text{T}}{\text{d}\text{e}\text{l}\text{t}}={10}^{-4}\frac{de{l}^2(T)}{del{x}^2}.$ The boundary

conditions are as $T(x,0)=80C,T(0,t)=200C,$

$-205\frac{dT(x,t)}{dx}{|}_x=1=90[T(1,t)-25]$

Develop the coefficient matrix using implicit scheme considering $x=0\mathrm{.}2,t=0\mathrm{.}5.$