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Cheatography

Conics Cheat Sheet (DRAFT) by

unit 4 notes math 5 yee haw slayy

This is a draft cheat sheet. It is a work in progress and is not finished yet.

circle

standard Form
(x-h)2 + (y-k)2 = r2
 
derived from distance formula
centre
(h, k)
radius
r

hyperbola

horizontal transverse axis (x coeffi­cient > 0)
(x-h)2/a2 - (y-k)2/b2 = 1
vertices
(h ± a, k)
foci
(h ± c, k)
asymptote
y-k=±(­b/a­)(x-h)
------­---­---­---­---­---­---­---­---­---­---­-----
vertical transverse axis (y coeffi­cient > 0)
(y-k)2/a2 - (x-h)2/b2 = 1
vertices
(h, k ± a)
foci
(h, k ± c)
asymptote
y-k=±(­a/b­)(x-h)
------­---­---­---­---­---­---­---­---­---­---­-----
transverse axis
passes through center vertex of both parabolas
a
distance from centre to each vertex
b
point on conjugate axis, not a point on hyperbola
centre
distance from center to each focus, c2=a2+b2
 

parabola

vertex
(h, k)
------­---­------------­---­------~~----­-------
opens up/down
(x-h)2 = 4p(y-k)
focus
(h, k+p)
directrix
y=k-p
opens up
p > 0
opens down
p < 0
------­---­------------­---­------~~----­-------
opens right/left
(y-k)2 = 4p(x-h)
foci
(h+p, k)
directrix
x=h-p
opens right
p > 0
opens left
p < 0
 

ellipse

horizontal major axis (a > b)
(x-h)2/a2 + (y-k)2/b2 = 1
vertices
(h ± a, k)
foci
(h ± c, k)
------­---­---­---­---­---­---­---­---­---­---­-----
vertical major axis (b > a)
(x-h)2/b2 + (y-k)2/a2 = 1
vertices
(h, k ± a)
foci
(h, k ± c)
------­---­---­---­---­---­---­---­---­---­---­-----
major axis
longer axis
minor axis
shorter axis
a
distance from centre to each vertex
b
distance from center to end of minor axis
c
distance from center to each focus, c2=a2-b2
length of minor axis
2a
length of major axis
2b