The question on the book “Creating a Neural Network” by Rashid T is the derivative of a quadratic function in the example correctly solved?

Question

Neural networks

Hi friends. I hope for the help of those who have studied this book and understood everything. Stuck almost at the end on what seems to be nonsense.
Screenshots are attached (page 114 of the book).

Answer 1

Yes, everything is correct in the example. The last line just warns that (f(g(x))' !=f'(g(x)), and f'(x)g'(x)