polynomial ring
where 
.
Given a commutative ring R with a multiplicative identity 1, a polynomial ring R[x] may be similarly defined. Factorization may be non-standard, though; note
and that x2−1 = 0 has four roots in ℤ8. If R is an integral domain, then the formula
holds. If R is a UFD, then R[x] is a UFD. If R is a field, then R[x] is a Euclidean domain. Polynomials rings such as R[x1, x2,…, xn] in several (or infinitely many) variables may similarly be defined.
- space-filling curve
- space–time
- span
- spanning set
- spanning tree
- sparse matrix
- Spearman's rank correlation coefficient
- special function
- special linear group
- special relativity
- spectral theorem
- spectrum
- speed
- speed of light
- sphere
- spherical angle
- spherical cap
- spherically symmetric
- spherical polar coordinates
- spherical triangle
- spherical trigonometry
- spheroid
- spiral
- spline
- splitting field