This is a very important step in the solution process since it will tell
you whether your answer, which is an estimate, is close to the correct
answer.
To check your solution, three things should be true about your distance function d(t):
For example, suppose the distance function you found is 

Then Again, since your d(t) is found from estimates of areas and interpolation of points, then your d(t) may not be exact but rather close enough. But what is close enough? So, if you find that your distance function is not close to correct, then you should go back and try to do it all again. 
Next: Follow the "Analytical Solution" link to the left. 