Just a quick question about notation. I was given the vector field F = r + grad(1/bar(r)) where r= (x)i+(y)j+(z)k. grad is just written as the upside down delta (gradient) and the bar I wrote in the above equation looks like an absolute value around just the r (although I don't know if it is absolute value). Basically I want to find the gradient of (1/bar(r)). What would be a simplification of this vector field so that I can solve the rest of the problem? I want to find its flux across the surface of a sphere. I think F would be ((x^3)-1)/x^2+((y^3)-1)/y^2+((z^3-1)/z^2, but I'm not sure.