FiveFive (5) is the natural number following four and preceding six.
While polynomial equations of degree 4 and below can be solved with radicals, equations of degree 5 and higher cannot generally be so solved. This is the Abel-Ruffini theorem. This is related to the fact that the symmetric group Sn is a solvable group for n ≤ 4 and not solvable for n ≥ 5.
Giving five refers to slapping hands with someone as a sign of approbation.
Five is also:
- the number of sides in a pentagon
- the number of Platonic solids.
- the number of dots in a quincunx
- the number of musicians in a quintet.
- the number of permanent members with veto power on the UN Security Council.
- almost all amphibians, reptiles, birds and mammals which have fingers or toes have five of them on each extremity.
- The Garden of Cyrus A Pythagorean Discourse based upon the number 5
See also: three, four, five, six, seven, integer, list of numbers.
This article is about the number. For the year 5 AD, see 5.
For the UK TV channel Five, see Five (TV).