- #1
rafaelpol
- 17
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Homework Statement
I am trying to follow a derivation in Jackson - Classical Electrodynamics
Homework Equations
In equation 1.58 (2nd/3rd edition) of Jackson - Classical Electrodynamics he says that by using the fact that [itex]\mathbf{\rho} \cdot (\mathbf{\rho} +\mathbf{n})/ | \mathbf{\rho +n|}^{3} = \nabla_{\rho}(1/|\mathbf{\rho}+\mathbf{n}|), [/itex] the integral [itex] \int {\mathbf{\rho} \cdot (\mathbf{\rho} +\mathbf{n})/ \rho^3 | \mathbf{\rho +n|}^{3}} [/itex] can be easily shown to be equal to to [itex] 4\pi [\itex].
The Attempt at a Solution
I can't really follow on how to solve this integral once the fact mentioned above is known. I know how to solve the integral using spherical coordinates, but from what I have seen that does not follow from what Jackson said at all. I am just curious if there is an easier to evaluate the integral using the gradient identity.