User blog comment:Tuner King 5/Help plz/@comment-24808864-20160112230745/@comment-24808864-20160112232135

But even with that, if you want to take the derivative with respect to n, you did so correctly on the exponential but essentially ignored the "n" that is inside the factorial on the other part! In other words, to find the correct derivative, you would need to perform a product rule with the exxponential and rational functions, and the rational function itself would have a product rule in it's denominator! Don't forget, if you take a derivative with respect to a particular variable, you must use the derivative rules for all instances of the variable in question!

You will need to go back to the drawing board and try to find the derivative again, before you can set that derivative to be zero.

And, if you do get the derivative correct, the only way you will be able to solve where it is zero is most likely going to be by using technology. The formula you will need to solve will be very...uhhhh...messy (for lack of a better word).