Something's going over my head. These are the steps when I attempt to do the problem, but the book's answer is Please and thank you.
Last edited by Remriel; Mar 18th 2013 at 01:45 PM.
Follow Math Help Forum on Facebook and Google+
Originally Posted by Remriel Look $\displaystyle x^2(1-2x)=x^2-2x^3$ so the derivative is $\displaystyle 2x-6x^2$.
Originally Posted by Plato Look $\displaystyle x^2(1-2x)=x^2-2x^3$ so the derivative is $\displaystyle 2x-6x^2$. Oh, I see. Thanks! I didn't realize I had to simplify the expression before I took the derivative.
You did not. Both methods work equally well. The problem occurs in your 3rd line: you didn't distribute the x^2 to the second part. So when that evalautes to -2(1), it should actually be, -2x^2.
View Tag Cloud