410 The Inverfe Method 
mX q—1X P? 
m—i X g—l— eX MA 
tg 
g—1 «Pt? 
M1 RK Slt xX a1 
- The value of -z-will be ‘found. of an -eafy farb- 
ftitution. 
After the fame manner: the equation of the 
curve, &c. &c. may be found, if three or more 
forces aét upon a body towards the fame centre. 
—— 0. 
Cor. If a==2, gon—I], £==P, and the 
|), BE 
force » be fuppofed to ac& from the 
WG J NIOCR ET at 
centre, or, which is the fame thing, —c be 
put for +c; then the equation for determining 
the diftance of the. apfides fromthe centre 
2+c—2m, , a 
MELT Ca 
will become y* — 
2m r* . 3 é hide 
=o. It is evident that one of the 
act 
values of y will be == r, andthe equation 
given above being divided by y—r, the quo- 
tient will be 9? rhe dice Se xr y + 
2m 3 
c 
diftance of the other apfe from the centre may 
be determined. 
r= 0; by folving which equation, the 
If 
