Modified Amperes law, maxwells equations

[Physicist_FTW]

Using the following identity curl(curl(B))=Grad(Div(B)-Grad^2(B) with maxwells equations in differential form in the absences of sources show that magnetic field obeys the wave equation Grad^2(B)- (1/(C^2))(d^2(B)/dt^2)


2. The main probelm is I'm not sure what form of B i should use, i think its

B=(U0/4PI)Intergral of ((dl[cross]r-hat)/r^2))

Could someone separate this into what it should look like as an x, y ,z vector i think then i could do this question.

 

[dx]

Hi Physicist_FTW,

The expression you wrote for B is only valid in magnetostatics, and is not one of Maxwell's equations. Maxwell's equations in differential form are the ones with the curls and divergences of E and B. You can find them here:

http://en.wikipedia.org/wiki/Maxwell's_equations