141 



quod , multiplicatione per du facta et integratione intra limites u = 1 et 

 u = a instituta, dabit 



l IA , = /, x Arc Cos J. 



Ordine integrationum permutato, evadit 



i o ' o 







Posito Ar = tg-^, obtinebimus 



U 



= f /2 + 2 Jlbos\^d^— ;//Cos%//^. 







At vero quum sit 



2 flCos\^d-b = A flhos^d^ = — p c l+L(i) — H(i), 



u 



//Cos ^d^= — H(t) = — f/2 , 







facile eruitur 



l (« + ,W + . v!) _ X(l) +777^ Arc Cos j . 



o 1 



Ponendo y = Arc Cos * , liabebimus 



f u Arc Cos i = / ydy 

 JKu*-i <Cosy ' 



unde denique secundum formulam (9) 



^2 Arc gin^ a z r2 Arc Sin|^ ^ 



