{"id":4043,"date":"2021-08-15T11:40:02","date_gmt":"2021-08-15T11:40:02","guid":{"rendered":"https:\/\/mathemerize.com\/?p=4043"},"modified":"2022-01-16T16:56:40","modified_gmt":"2022-01-16T11:26:40","slug":"what-is-inverse-relation","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/what-is-inverse-relation\/","title":{"rendered":"What is Inverse Relation – Definition and Example"},"content":{"rendered":"
Here you will learn what is inverse relation, identity relation and posets in relation with example.<\/p>\n
Let’s begin –<\/p>\n
If relation R is defined from A to B, then inverse relation would be defined form B to A, i.e.<\/p>\n
\nR : A \\(\\rightarrow\\) B \\(\\implies\\) aRb where a \\(\\in\\) A, b \\(\\in\\) B<\/p>\n
\\(R^{-1}\\) : B \\(\\rightarrow\\) A \\(\\implies\\) bRa where a \\(\\in\\) A, b \\(\\in\\) B<\/p>\n<\/blockquote>\n
Domain of R = Range of \\(R^{-1}\\)<\/p>\n
and Range of R = Domain of \\(R^{-1}\\)<\/p>\n
\\(\\therefore\\) \\(R^{-1}\\) = {(b, a) | (a, b) \\(\\in\\) R}<\/p>\n
A relation R is defined on the set of 1st ten natural numbers.<\/p>\n
e.g. N is a set of first 10 natural numbers.<\/p>\n
aRb \\(\\implies\\) a + 2b = 10<\/p>\n
R = {(2, 4), (4, 3), (6, 2), (8, 1)}<\/p>\n
\\(R^{-1}\\) = {(4, 2), (3, 4), (2, 6), (1, 8)}<\/p>\n
Identity Relation<\/h2>\n
A relation defined on a set A is said to be an identity relation if each and every element of A is related to itself & only to itself.<\/p>\n
e.g. A relation defined on the set of natural numbers is<\/p>\n
aRb \\(\\implies\\) a = b where a & b \\(\\in\\) N<\/p>\n
R = {(1, 1), (2, 2), (3, 3), ……}<\/p>\n
R is an identity relation<\/p>\n
Posets<\/h2>\n
A relation R on a set P is called an partial relation order if it is reflexive, antisymmetric and transitive. That means that for all x, y and z in P we have:<\/p>\n
\n
- x R x;<\/li>\n
- if x R y and y R x, then x = y;<\/li>\n
- if x R y and y R z, then x R z.<\/li>\n<\/ul>\n
The pair (P, R) is called a partially ordered set, or for short, a poset.<\/p>\n
Two elements x and y in a poset (P, R) are called comparable if x R y or y R x.<\/p>\n
If any two elements x,y \\(\\in\\) P are comparable, so we have x R y or y R x, then the relation is called a linear order.<\/p>\n\n\n