(d(d(7*10^8 - 4.2*10^(-6)*((y^2 + 2*x^2)/((x^2 + y^2 )^(1/2) ) )))/(dx))/(dx)

Uh oh! Wolfram|Alpha doesn't run without JavaScript.

Please enable JavaScript. If you don't know how, you can find instructionshere.Once you've done that, refresh this page to start using Wolfram|Alpha.