c. 









c" 



A' 



^, ^ 



c 



-oo 



-xV 



WV 



" 











(-t~)C" 







C" 



iZ dl 



C" 



Figure 187 - Diagram for oblique incidence on a plate. See Section 114. 



[114a] 



(t - cos a ) 

 Then, from Equations [113a] and [114a], 



dz = - Cdw = {t + y/t^ - 1) 



2 c dt 



{t - cos a ) 



[114b] 



After integrating, by means of the substitution w = (< - cos a ) ^ and choosing c and the 

 constant of integration to make z = - 1/2 for il = + 1, it is found that 



7 ■ ^ 



i Sin 



4 + 77 sin a 



[114c] 



I 



4 + TT sina 



+ sin ct sin 



cos a -2t 

 (t - cosa) 



t cos a - 1 



. t cos a - 1 9 1/2.7 



1^0+ (;; - 1) sin^a 



(t - cos a) 



t - cos a 



+ cos a (3 - cos a ) 



[114d] 



286 



