There is no forum for basic calculus, so I will have to post in the university-level forum. I have been trying to refresh my maths for the last few months (I had forgotten everything, right down to how to do long division.) and I feel as if I have been making good progress.
I have a question about a very simple differentiation exercise:
Using the formula
find the derivative of
Here is my attempt at a solution:
It would be great if someone would tell me where I am going wrong.