A=C
relationship in circle
A=0 xor C=0
relationship in parabola
AC>0
relationship in ellipse (A not equal to C)
standard form circle
(x-h)^2 + (y-k)^2 = r^2
general form of a circle
x^2+y^2+ax+by+c=0
p
distance between vertex and focus/ vertex and directix
2p
distance between focus & directix
4p
length of latus rectum
(y-k)^2=4p(x-h)
horizontal parabola
(x-h)^2=4p(y-k)
vertical parabola
p>0 (horizontal)
opens right
p<0 (horizontal)
opens left
p>0 (vertical)
opens up
p<0 (vertical)
opens down
c^2=a^2-b^2
equation for c
a
distance between vertex and center
a>b
relationship between a and b
b
distance between co-vertex and center
c
distance between center and focus
(x-h)^2/a^2+(y-k)^2/b^2=1
horizontal major axis
(x-h)^2/b^2+(y-k)^2/a^2=1
vertical major axis
2b^2/a
latus rectum of ellipse
c/a
eccentricity