[ 577 ] 
Confequently OP *+ 0 ^ being = «-(-« + tf— « , 
and « x P ^x Ck! xC k", fee. = 2 an x VT^f 
x V &)' + f\ fee. when n is an odd number ; 0 P” -f- 
O ^ will then be = » x P Qx Ctt x C £", fee. where 
the diameter P ^ takes place indead of the infinite 
n + 1 
2 
quantity C £. 
But if » be an even number, OP^-f-O^ will be 
= 2xCf xC &c. 
XIV. 
It is obvious that, of the fadors C k\ C k!\ &c. the 
firft and laid, the fecond and lad but one, &c. are re- 
fpedively equal to each other : Therefore the fquares 
of the fadors below P and the fquares of their 
values, being omitted, 
O P n O ^ is — n x P ^x C£* x C &"■*, fee. and 
<2 4~ « + a — (a — 2 an x co 2 + b* x & z ~r c*, fee, 
when ?z is an odd number 5 or 
O P n + o is = 2 X C£' z X cr\ fee. and 
n n . - 
# 4 - w ~ir a — co — 2 x co z ~\-t> z x»*+fV& c. when 
n is an even number. 
XV. 
Writing in the equation «— 2 y x a-j-co x 
_ ft 2 n — . . 
a — « + — co = 2 + 2 y x «* -j- x -f- £*, fee. 
4 D found 
