equation icon  2 integral 2 integral C± [f ] = lim e-d- d± (s + e)f (x)d4x = lim e-d- f(±-R,-x)-d3x e-->0+ de2( ) e-->0+ de2 R integral ¨f f f integral (1 ) = lim e ---± 3---+ 3--- d3x = 2p d3(x) -r2¨f ± rf + f d3x e-->0+ R3 R4 R5 3 = 2pf (0,0),