cof. ZC 
Mr. Wildbore on 
... — r the fluxion of the time, gives the fluxion of 
y x cof. AZ — x x cof. BZ 
rj cof.ZC x x cof. AZ-f- y X cof. BZ 
the angle deferibed by C about Z _ ^ * co f. az -* x cof. BZ 
cof- zc x b ■ x c o f. AZ~ + a~ x_cof_ZB_ ^ which in terms of ZC is by 
— f. ZC 1 ^-^xcof. ZAxcof. ZB 
cof. ZC 
computation = y-^rr * 
ba' x f. ZC z -bxV- rX s 1 . 
a f-CV'-l'.ZC v' n 1 — cof.ZC 1 ’ 
•where r and « = the fine and cofine of CW, and f. CV‘=> 
Now, this being the fluxion of the arc to ra- 
Vs 1 a z -c 
. X 
** b 
% c z 
dius i, which is the meafure of the angle deferibed by C about 
Z in the time t ; this arc in value therefore will be double the area 
of the fedfcor of the circle whofe radius is unity deferibed about 
Z in the fame time. Hence, having found a fedlor ot a circle 
to radius unity, whofe area is half the fluent of the above 
fluxion, or the fluent of half the above fluxion, the arch-line 
of this fector will be the meafure of the required angle de- 
fen bed by C about Z in the time /• 
L et a - cof :. 70 7 _, A being the arc, beginning when n = 
cof. zc an q ra( 3i us unity, and B = 
V n 2 — cof. ZC 
cof. ZC, whofe cofine = 
-f. zc 
n 
- B being - the arc, beginning whenCVrrZC, 
vi. cv*-f. zc J ’ 
whofe cofine — and radius unity, and in fig. 12. take ZY 
cof. ZC 
ia’xf. Z C’-Jxs'-t'xi 
fuch that ./Sc x Z7 X f. zc* Vi . CV* - f. ZC’ 
may = A x — the fluxion of the curvilinear area deferibed 
about the centre Z and bounded by the ordinate ZY, whofe lirft 
value is ZG when n = cof. ZC, and A = o; on ZG take 
a 
