Plus or Minus
The symbol 
is used to denote a quantity which should be both added and subtracted, as in 
. The symbol can be usedto denote a range of uncertainty, or to denote a pair of quantities, such as the roots given by the Quadratic Formula
When order is relevant, the symbol
is also used, so an expression of the form 
is interpreted as 
or
. In contrast, the expression 
is interpreted to mean the set of four quantities 
, , , and 
.See also Minus, Minus Sign, Plus, Plus Sign, Sign- Oblique Angle
- Oblong Number
- Obstruction
- Obtuse Angle
- Obtuse Triangle
- Ochoa Curve
- Octacontagon
- Octadecagon
- Octagon
- Octagonal Number
- Octagram
- Octahedral Graph
- Octahedral Group
- Octahedral Number
- Octahedron
- Octahedron 5-Compound
- Octahemioctacron
- Octahemioctahedron
- Octakaidecagon
- Octal
- Octant
- Octatetrahedron
- Octic Surface
- Octillion
- Octodecillion