This is a calculus question, but I understand how the differentiation here works. What I don't understand is the simplification, which is generally algebra, so I posted it in this forum. I just can't figure out how they have done the simplification? I can get the end of the first line, but how they simplify it to the final outcome, can anyone help me understand? The second line I have no idea... how does -x^(3/5) suddenly become -5x/5x^(2/5)?