English
Noun
wikipedia
plus-minus sign
#mathematics the symbol ±, meaning "plus or minus", used to indicate the precision of an approximation (as in "The result is 10 ± 0.3", meaning the result is somewhere between 10 - 0.3, that is, 9.7, and 10 + 0.3, that is, 10.3), or as a convenient shorthand for a quantity with two possible values of opposing sign and identical magnitude (as in "The roots of the equation x² - 4 = 0 are ±2").

See also
minus-plus sign

• 2005-08-18 17:14 - Paul G - improved def; examples; see also

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