Hello, today my teacher presented us with the concept of derivatives. I was okay in class, but when I got home, I was completly lost. Using the definition (f(x+h) - f(x))/h, we have to fine the derivative of y=2x^2 - 5. I know the answer is 4x from the back of the book, but I cant understand how to get it. Am I factoring something wrong? I get to a point of simplification that everything just cancels out. Your help is greatly appriciated!