the tension of overhead vdres supported by equidistant pjoles. 205 

 Wo have further 



?/ I — 2a; 



= 1 + 2x + 2'x' + Vijr + 2^'j^ + ... , 

 which iH also convergent when 



\x\<\. 



P f ^ 1- 3. 5. ..(2m -3) 

 But &,, = ^j 



and HO wo may write 



1 , ^, 2.4, „ 2.4.6, , 



v'' 1 1 . o 



We have, however, on the other hand 



^ = 1 + 26i X + (36/'^ + 26,) ^;'' + (46r + 66,6, + 26,) *■'' + 

 Equating coefficients we get 



2(^-1 



while 6i = 1. 



We shall next show that if m > 2 



4 . 6 . 8 . . . 2w 



< fn?. 



2m 2m 4- 1 

 2m — 1 2m — 1 ' 



