Plxo » Yo 20) 
Woe, Ys z) 
p(x, y 2) 
Figure 9. Source and a solid rectangular parallelepiped. 
Because of the extreme difficulties in evaluating the above 
triple integral when the source is a finite distance from 
the array, the integral is evaluated for a source at infinity: 
+y(cos8- cos8>o )+z(cosy- cosyo ) J | dxdyadz 
Integrating (letting Z(x, y, z) = constant) 
i at ; : bt ~ 
ia sin (Zi (cosa- COSA) )) sin (Gicoss- cos8o )) 
~ (cosa- COS ) + (cos8-cos®o ) 
_ (en 
sin( "(cosy -cosyo )) 
Tr 
7 (cosy-cosyo) 
28 
