Mike Armstrong wrote:
Very informative response Werner as usual.
... and wrong, too :-( The way the two parts are joint, namely without a step, if the derivative would get zero, it would yield the absolute maximum. I was playing around with the function and suddenly look at an Mu_total with a decent step in it - that way I was misead to the remark.
BTW, here is a closeup of the position where the two parts join and we clearly see the kink Alan was talking about. So it obviously won't help looking for a horizontal tangent.
I still meditate over the error message and wondering why we don't simply get the standard "This calculation does not converge to a solution" error. Obviously the error is thrown by the derivative calling the function, but what would root feed into the function as argument that it would not be allowed to be compared to length a. I already tried a unitless variant but with the same error message.