2. CONIC SECTION
In mathematics, a conic section (or just
conic) is a curve obtained by intersecting a
cone (more precisely, a right circular conical
surface) with a plane. In analytic geometry, a
conic may be defined as a plane algebraic
curve of degree 2. It can be defined as the
locus of points whose distances are in a fixed
ratio to some point, called a focus, and
some line, called a directrix.
3. CONICS
The three conic sections that are created
when a double cone is intersected with a
plane.
1) Parabola
2) Circle and ellipse
3) Hyperbola
4. CIRCLES
A circle is a simple shape of Euclidean
geometry consisting of the set of points in a
plane that are a given distance from a given
point, the centre. The distance between any
of the points and the centre is called the
radius.
6. PARABOLA: LOCUS OF ALL POINTS WHOSE
DISTANCE FROM A FIXED POINT IS EQUAL TO
THE DISTANCE FROM A FIXED LINE. THE FIXED
POINT IS CALLED FOCUS AND THE FIXED LINE IS
CALLED A DIRECTRIX.
P(x,y)
13. ELLIPSE: LOCUS OF ALL POINTS WHOSE SUM OF
DISTANCE FROM TWO FIXED POINTS IS
CONSTANT. THE TWO FIXED POINTS ARE CALLED
FOCI.
14. ELLIPSE
a > b
Major axis:
Minor axis:
Foci:
Vertices:
Center:
Length of major axis:
Length of minor axis:
Relation between a, b, c
21. ECCENTRICITY IN CONIC SECTIONS
Conic sections are exactly those curves that,
for a point F, a line L not containing F and a
non-negative number e, are the locus of
points whose distance to F equals e times
their distance to L. F is called the focus, L the
directrix, and e the eccentricity.
22. CIRCLE AS ELLIPSE
A circle is a special ellipse in which the two
foci are coincident and the eccentricity is 0.
Circles are conic sections attained when a
right circular cone is intersected by a plane
perpendicular to the axis of the cone.