539 





^ = ^3 + i?, ; - /^ = ^, 



Eliminating tlie constants A, £ two equations in «j, «, are obtained. 

 These may be written in the form : 



Ö, — He 



R,-H, 



'A '^^^'h^-'^^h^ 



«(^) 



^,{o.,-^?,^^^^i^ 



\/h ;a(«''+v'a r @ ('h}^li\ _ f)('hïli\ 



Since ;?, is very large the comparison of the first two expressions 

 with each other shows that («,' — '(i'),^, must remain finite. Tlius 

 writing 



/i, («,-«,) zr= y , («, +fO = 2« .... (16) 



and considering onlj' tlie case of very large values of /i, we have 

 H, — He H, — He 



T\/¥n«-^y<m 



lim 



The limit last written is taken under the conditions (16), the 

 quantities «,y being kept constant. It is easily found that the Lim 



in question is 



ay 

 2 ^2—1 



