386 The Inverfe Method 
In the laft cafe, when m is lefs than 
unity, the equation of the trajectory is p= 
bf PY 
» anda sh ; 
rT f 
1—m y 
ah ey os | 
—~——_—_____———_——.._ It is evident that when 
4 r?>—mP* 
Be Gs as oi are 
1—m 
y=, eo the body may therefore defcend. to 
xP 
the centre; but if y be infinite, v= ube 
—1 
therefore the body cannot afcend to an infinite 
height. It is likewife evident from the above 
equation, that when y increafes, p increafes ; 
but p can never exceed y, therefore when they 
are equal, that is, at an apfe, y will be the 
greateft poffible ; but then y== dfs ca at ask 
anes, CN 
Wherefore, after the body has paffed an apfe, it 
will defcend to the centre. 
Beeaufe Se epre ke “Ae 
rey telcgroe Se ae ay 
rect fluent being taken, os a equation re- 
duced 
, the cor- 
