Quote:
Originally Posted by Sandes
I
Perhaps I'm going in the wrong direction but one of the things I realized is that the constraint could be restated as minimizing h^2 2 h yn summed over all N but that could be going off in completely the wrong direction.

This is the right idea. Your hypothesis h is just a number in this case. Ein is a function of this number (variable) h. One way to minimize a function of a variable h is to take the derivative and set it to zero.