264 



PROFESSOR A. G. GREENHILL ON THE 



Region. 



A. 

 > c > v/5 + 2. 



B. 

 v/5 + 2 > c > 1. 



(2c - 1 + ye) (2 C + i - yc) (ye + 



2c 



c 3 + 



2c 

 v/C + 1 



x/C - 1 

 v/C + 1 



V /C -Jl 



c 2 + 



c 3 - 

 2c 



(c + 3)(-c 3 + 4c4- 

 20c ^ C 



(3c- l)(-c 2 + 4c+ 



3c 3 + 7c 2 + c 

 20c 



(c + 1) (c - 



cnfK 



cnfK 



sn|K 



nd |K 



@0 



snfK 



cn|K 



dnfK 

 cnfK 



dn|K 



znfK 



zs|K 



zsfK 



K 



_ 

 @K 



