Chapter 9 Flashcards
point slope formula
y-y(1)= m (x-x(1))
(x-h)^2=4p(y-k)
opens up or down
a parabola opens up if
p>0
a parabola opens down if
p<0
(y-k)^2=4p(x-h)
opens right or left
a parabola opens right if
p>0
a parabola opens left if
p<0
focus
P from vertex
inside parabola
distance formula
d=sq root of (y1-y2)^2 + (x1-x2)^2
d1=d2
distance from given point to focus=distance from focus to tangent line’s y/x intercept
how to tell if ellipse/circle
B^2 -4AC<0
how to tell if parabola
B^2-4AC=0
how to tell if hyperbola
B^2-4AC>0
how to tell if hyperbola transverse axis is horizontal (right and left)
[(x-h)^2/a^2] -[(y-k)^2/b^2]
x comes first
how to tell if hyperbola transverse axis is vertical (top and bottom)
[(y-k)^2/a^2]-[(x-h)^2/b^2]
hyperbola: foci are ___ units from center
c units from center
c^2 = a^2 + b^2
foci = (h+/- c, k)
(h, k+/-c)
slope of asymptotes in hyperbola
and how to find asymptotes
if vertical:
y=+/- (b/a) • (x-h)
if horizontal:
y=+/- (a/b) • (x-h)
general form of conics
Ax^2+Cy^2+Dx+Ey+F=0
circle, using general form
A=C
parabola, using general form
AC=0