User:SamHB/Injection (mathematics)

<math>x^{2}-5x+6=0</math> <math>x=?</math>

This article/section deals with mathematical concepts appropriate for a student in mid to late high school.

Note: This article has wikilinks into my sandbox.
These need to be changed if it is moved to the main article space.

An injection or injective function is a mapping (or function) between two sets, that is "one-to-one". This means that it never maps two different points in the domain to the same point in the range.

In other words, an injection from set A to set B is a mapping such that every element in A is mapped to a distinct element in B. For example, one injection from the set {X, Y, Z} to the set {1, 2, 3, 4}, maps: X to 1, Y to 2, and Z to 3. If we were use this map instead: X to 1, Y to 2, and Z also to 2, it would fail to be one-to-one because Y and Z both map to the same result.

For further information, see bijection