^\ 1 + 2(mK)^^^ cos 6 + [l+4(mK) "'"''^ cos 9] 



1/2 



2 m cos 



2 TT 



(112) 



The integral path of u is given in Figure 5. 



"3 



"4 1-2 



Figure 5 - Integral Path when cos 6 < 1 



By substitution of Equation (111) into Equation (107), G„ (x,0,0) is 



G2(x,0,0) 



/ r r° r^^^ r \ 1/2 1/2 ^ 

 ^l \ de I du + I de J du j ^ -^ u cos 6) exp(-ixu cos 6) 



u - (K +m u cos 6) 



tt/2 . 



^ r d0 du 



2^ J -( 



(K -m u cos 9) exp(ixu cos 6) 



,^1/2 1/2 Q.^ 

 u - (K -m u cos 0) 



(113) 



With the following expansion 



(K 



'^^^±m^^^u cos 6) = K + u cos 6 [mu cos e±2(mK)-'"' ^] 



Equation (113) can be rewritten 



30 



