Okay guys, this is driving me absolutely nuts. I'm working on finding derivatives using the product and quotient rules and the book will sometimes simplify the problem before finding the derivative but sometimes wont and I don't understand why. For example: The function y = (v3-2v√v)/v The book simplifies it to v2-2v½ and then gets 2v-v-½ as the derivative without even using the product or quotient rules. Then on this problem: f(x) = x/[x+(c/x)] it doesn't simplify first. I started off by simplifying it as follows: Original function: f(x) = x/[x+(c/x)] Making the bottom all one fraction: x/[(x2+c)/x] Bottom and top cancel out: 1/(x2+c). But using the quotient rule on this gives me an answer of 2x/(x2+c)2, which is wrong. The answer is actually 2cx/(x2+c)2, which the book gets by using the quotient rule without simplifying first. When is it okay to simplify before finding the derivative and when isn't it?