of Projectiles. 6j

e \ CO R. VIII.

Hence, if the Impetus As and De-.: pression of the Plane Y A X are given,

1 it will still be R — S\ Y AX: R :: 2, AsK\ : AX, for R:S,Y AX :: AXiXY^

* and by Division, (because A X= z A J

+JX)R-S',YAX:R::iJf:AX

f,\ ■ COR. IX.

; Hence also, it’s evident that if thej Distance AX {Fig. 19.) is taken less■frj than the greatest Distance the Impe-p tus can reach, the Circles describ’d onA, and X y with the Radii As and XK,will intersect each other in two Points/and F, equally distant from the Point,J 'by where the Focus of the Parabolawou’d be if A X was the greatest Di-(C j stance that I mpetus cou’d reach 5 which

j Points/and F, will be the Foci of two

is, Parabola’s describ’d by that Impetus,{< K i each