α

V

m

Lower nappe

Upper nappe

Axisl

Generator

Plane

Cone

βαα

V

m

Lower nappe

Upper nappe

Axisl

Generator

O

P(x,y)

Radius

(h,k)C

P(x,y)

O(0,0)

x² + y² = r² (x – h) ² + (y – k) ²

α β

PP P

F F

¹³²

²¹

α β

O

(0,c)

(0,-c)

(-b,0) (b,0)

(0,-a)

(0,a)

Y

x² y²

a² b²

——+ = 1x²

y²

b² a²

——+ = 1

(-c ,0

)

(c, 0)

FocusOX' X

Y'

Y

•P

(x,y)

Directrix

α

β

F(a,0)O

x =

-a

y² = 4ax

X' X

Y'

Y

F(-a,0) O

x =

+a

y² = -4ax

X' X

Y'

Y

F(0,-a)

O

y = a

x² = 4ay

X' X

Y'

Y

F(0,a)

O

y = -ax² = -4ay

X' X

Y'

Y

Transverse axis

F

Conjugate axis

F

Centre

Vertex Vertex

²¹

α β

Transverse axis

F

Conjugate axis

F(c ,0)(a ,0) ( -c ,0) (-a ,0)

O

F

F (0 ,c)

(0 ,a)

(0 ,-c)

(0 ,-a)O

¹

¹

²

²