[ 3 i 5 ] 
equal to nothing : which will give the value of z 
equal t0 ^ or fame with the value of 
z at the points or contrary flexure. 
I 3 * P°i nts °f contrary flexure, the ratio of 
the fluxion of C f to the fluxion of Q is greatefl 
m comparifon of the ratio of the fluxion of Q t to 
the fluxion of F/. This is proved by finding the 
value of z when the fluxion of the former ratio 
divided by the latter, or of 
. t 
I — 
2 2 * 
n 2i 
TTSf * 
p 1 ' ~ 
’-—l 
n — a 
n z 
I — 
P 9 
1/ 
p i 
-.The 
is nothing, which will {fill give z ~ 
^ n i — n 
reafon, therefore, in the nature of the curve, which, as 
the ordinates flow, keeps at firfl the excefs of Ft above 
Q t lefs than the excefs of Cf/ above C operates 
with its greatefl force at the points of contrary 
flexure, J 
20. The greatefl part of the area R QW h lies be- 
tween Rtf, and the ordinate at the point of contrary 
flexure. By Art. 1 1 the ratio of R£/Qto RQW/j jg 
XG X “ 
*+ I A/ 2 
7tl 
+ 
2 m 
X - 
3 1 2 n - 5 
&c - Subflitute here \! -r 1 - for z, and ■ ■■ 
* C trr n n V * K X H 
lor G (K being the ratio of the quadrantal arc to 
* This is always the true value of G j but it would be too 
tedious to give the demonftration of this here* 
S f 2 , 
tadius. 
