Now, I have to count derivative from :
it would of course not be a problem IF the result would not be:
So, obviously it is the whole procedure including the proof of the rule for the derivative of the rational function and that is what I am asking about.
(Of course I am avare h is almost 0, but I am interested to the whoel procedure how didi they get it!)
I tried like this:
and got of course:
can someone help?
Did I make a mistake?