258 MATHEMATICAL FORMLILE AND ELLIPTIC FUNCTIONS 



A ' ' ^ ~ - - = A(fK >) = I 7r(l _ /) _ K znfK' 



= B(fK') = %irf+K zufK' 



5 3 (7 - S T/S 



A + B = JTT. 



sn 2 fK' = 



s a 

 B. r^A/^S^ ds 



dn 2 /^ 7 = - 



Si - (7 



C. 



oo >s >s,J %_ q . ^ = C(fK') = K zsfK' 

 --^ = D(fK>) = 



S (7 



D - C = |TT. 



