Use of the product and quotient rule in differentiation In the process of rounding up the product and quotient rule, I got confused when my textbook said that the product rule should not be used if one of the factors of the product is a constant, and the quotient rule should not be used if the denominator is a single term. I've used the rules for both of these conditions and i got the answers right, the only thing was that it took longer to solve, so the question is can I still use the product and quotient rule under such conditions?

When on of the term is a constant, it is equivalent to using linearity to factor out the constant. Therefore, it is unnecessary use of product and quotient rule, but not false.
