$T(x,t)=\frac{1}{2\sqrt[\phantom{2}]{t}}{e}^{-\frac{x^2}{4}t}$

that we derived in class. The function should return the mean square of the difference between your

solution and the approximate solution.

Submit the code to Matlab grader and a PDF of your solution $($including the code$)$ and a plot with

$N=20,L=20,=1,$ and $t=3.(100$ points$)$