⭕ Conic Sections

1. Introduction

Conic sections are the curves obtained by intersecting a right circular cone with a plane. They include circles, ellipses, parabolas, and hyperbolas.

2. Circle

The set of all points in a plane that are at a fixed distance (radius r) from a fixed point (center h,k).

(x - h)² + (y - k)² = r² Standard equation of a circle.

3. Parabola

The set of all points equidistant from a fixed line (directrix) and a fixed point (focus).
Standard form (opening right): y² = 4ax. Focus: (a, 0). Directrix: x = -a. Latus Rectum: 4a.

4. Ellipse

The set of points where the sum of distances from two fixed points (foci) is constant.
Standard form: (x²/a²) + (y²/b²) = 1.

Ellipse Properties

Eccentricity (e): c/a. For ellipse, e < 1.

Relation: c² = a² - b².

Length of Latus Rectum: 2b²/a.

5. Hyperbola

The set of points where the difference of distances from two fixed points (foci) is constant.
Standard form: (x²/a²) - (y²/b²) = 1.
Eccentricity e > 1. Relation: c² = a² + b².