I don't know why I'm stuck on this problem or why I keep getting it wrong. The answer in my book is -2z/(z^2+1)^2, but I ended up with -(z^2+1)(2z)/(z^2+1)^2 I don't understand where the whole z^2+1 in the numerator goes to. Isn't that how it's supposed to be chained? g(x) multiplied by g'(x)? Here's the work: 0(z^2+1) - (1)(z^2+1)(2z)/(z^2+1)^2 -(z^2+1)(2z)/(z^2+1)^2 Could someone explain what I'm doing wrong?