Null (mathematics)

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See also Null for use in computing and other fields

In mathematics, the word null (from German null and Norwegian null, which is from Latin nullus, both meaning "zero", or "none"). Meaning of or related to having zero members in a set or a value of zero. Sometimes the symbol ∅ is used to distinguish "null" from 0.

In a vector space the null vector is the zero vector; in set theory, the null set is the set with zero elements; and in measure theory, a null set is a set with zero measure.

A mathematical mapping is said to be null potent (or nilpotent) if repeated application can map the whole domain into the null element.

A null space of a mapping is the part of the domain that is mapped into the null element of the image (the inverse image of the null element).

In statistics, a null hypothesis is a proposition presumed true unless statistical evidence indicates otherwise.

References

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Last updated on Friday March 07, 2008 at 14:39:44 PST (GMT -0800)
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