Page 58 - Aeronautical Engineer Data Book

Fundamental dimensions and units 45
y axis

D P

x axis
Directrix Focus S(a,0)

Fig. 2.10 Parabola

y axis

P
D
b
x axis
Directrix S(ae,0) b

a a

Fig. 2.11 Ellipse
y axis

Directrix D P

S x axis
Directrix S(ae,0)

a a

Fig. 2.12 Hyperbola