Fourier Cosine Series
If 
is an Even Function, then 
and the Fourier Series collapses to
 | (1) |
 |  |  | (2) |
 | |  | |
|  | (3) |
where the last equality is true because
 | (4) |
, | |  | (5) |
| |  | (6) |
See also Even Function, Fourier Cosine Transform, Fourier Series, Fourier Sine Series
- Rotation Matrix
- Rotation Number
- Rotation Operator
- Roth's Removal Rule
- Roth's Theorem
- Rotkiewicz Theorem
- Rotoinversion
- Rotor
- Rotunda
- Rouché's Theorem
- Roulette
- Round
- Rounding
- Routh-Hurwitz Theorem
- Routh's Theorem
- RSA Encryption
- RSA Number
- Rubber-Sheet Geometry
- Rubik's Clock
- Rubik's Cube
- Rudin-Shapiro Sequence
- Rudvalis Group
- Rule
- Ruled Surface
- Rule of 72