I'm not sure what this means.
-2r^2-r-1; -1
Can you explain what you are trying to do? Guesing from your title, are you trying to calculate the derivative of -2r^2-r-1 at r = -1?
Here are some examples on how to do differentiation with Wolfram|Alpha:
http://www.wolframalpha.com/examples/Derivatives.html
