If I apply the derivative operator to x squared, I get 2x. Now, if I also apply the derivative operator to x squared plus 1, I also get 2x. If I apply the derivative operator to x squared plus pi, I also get 2x. The derivative of x squared is 2x. The derivative with respect to x of pi of a constant is just 0. The derivative with respect to x of 1 is just a constant. It's just 0.