Biharmonic function squared

We generated a biharmonic function and squared it, and then attempted to approximate it using $\psi$ functions on level 4. Here are our results:

This is the function we are trying to approximate:

This is a graph of our approximation attempt, notice they look rather similar

This is a graph of of the difference of the two functions. This graph is not on the same scale as the other two. The maximum of the other two graphs is about 2.9 while the maximum of the difference graph is about .04. So our approximation was good on the boundaries and excellent everywhere else.

All in all, this was an excellent approximation, and we were happy with the results.