Conic Sections Flashcards
(32 cards)
straight line intersects at a fixed point and rotates about it
double right circular cone
fixed point
vertex
line that rotates around the vertex
generator
fixed line, perpendicular to the base
axis
perimeter base
directrix
lateral surface of cone; consists of upper and lower
nappes
a<b; angle between plane and axis (b) is greater than vertex angle (a)
ellipse
plane perpendicular to axis; special type of ellipse
circle
a=b; angle made by plane and axis is equal to the vertex angle; open curve
parabola
plane intersects one nappe - a>=b
intersects 2 nappes - a>b
disjoint curves
hyperbola
intersects at vertex
ellipse becomes a point
parabola is a line
hyperbola becomes two intersecting lines
degenerate
circle standard equation
(x-h)^2 + (y-k)^2 = r^2
diameter of a circle
2r
area of a circle
πr^2
point at which the curve touches with the x-axis
tangent
horizontal parabola standard equation
p: (x-h)^2 = 4p (y-k)
-p: quadratic function
vertical parabola standard equation
-p: (y-k)^2 = 4p (x-h)
p: not a function
parabola
end points of latus rectum
2|p|
ellipses standard equation
horizontal major axis
(x^2 / a^2) + (y^2 / b^2) = 1
ellipses standard equation
vertical major axis
(x^2 / b^2) + (y^2 / a^2) = 1
parabola
focal distance; distance from f to v
p
ellipses
distance from center to one vertex
a
ellipses
distance from center to one co-vertex
b
ellipses
distance from center to one focus
c