Ellipse Caustic Curve
For an Ellipse given by
 |  |  | (1) |
 | |  | (2) |
with light source at
, the Caustic is | |  | (3) |
| |  | (4) |
where
 | |  | |
 |  | ||
|  | (5) | |
 | |  | |
|  | (6) | |
 | |  | (7) |
 | |  | |
|  | (8) |
At
, | |  | (9) |
| |  | (10) |
- Semidirect Product
- Semiflow
- Semigroup
- Semi-Integral
- Semilatus Rectum
- Semimagic Square
- Semimajor Axis
- Semiminor Axis
- Semiperfect Magic Cube
- Semiperfect Number
- Semiperimeter
- Semiprime
- Semiprime Ring
- Semiregular Polyhedron
- Semiring
- Andrews-Curtis Link
- Andrews-Schur Identity
- Andrew's Sine
- Andrica's Conjecture
- André's Problem
- André's Reflection Method
- Anger Function
- Angle
- Angle Bisector
- Angle Bisector Theorem