of Central Forces. 409 
pear that ! 
mm P? rt oi 
Pp oo ; = 
mm—m—m X ye mrt—y"—-9- mr 
mm P* yI—* 
fies — ii ee > i + mri yi + mrt 
+1 n-}1 9 Att 
Suppofe ta ae then fince —— 
i 41—1 Xr * 
2m B+ m Arr 
= (v? = ) is = 
q—1 Xr 1 
& Eeimead bee » OF, = — 3 hence 
q—1 xX ri- eth ¢-—1 
‘ g—1!i % ™m : ? 
m= 7 ‘If therefore this value of 
x n—l 
m, be fubftituted in the above value of 9’, 
there will arife for the general equation of the 
curve . ; 
: m Py jGize 
Pp 22 ee eas eae ———————————_— 
n— n—1 
lida haa 11y"—1.4 m—1—cX Be 
If p be ee =y, then the equation for 
"determining the diftance of the apfides from the 
centre of force will become y*—* + 
eX n—1 11 
St gd em td 
Eee —m 
yr 1 
oem 
