2^(n^2+n)/2 is the number of symmetric relations on a set of n elements.
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relation and function are number that combine with number and neqative number to .
make a table as I did below for the set {a,b,c} with 3 elements. A table with all n elements will represent all the possible relations on that set of n elements. We can use the table to find all types of relations, transitive, symmetric etc. | a | b | c | --+---+---+---+ a | * | | | b | | * | | c | | | * | The total number of relations is 2^(n^2) because for each a or b we can include or not include it so there are 2 possibilities and there are n^2 elements so 2^(n^2) total relations. A relation is reflexive if contains all pairs of the form {x,x) for any x in the set. So this is the diagonal of your box. THESE ARE FIXED! No, in reflexive relation we still can decide to include or not include any of the other elements. So we have n diagonal elements that are fixed and we subtract that from n^2 so we have 2^(n^2-n) If you do the same thing for symmetric relations you will get 2^(n(n+1)/2). We get this by picking all the squares on the diagonal and all the ones above it too.
the total no of reflexive relation on an n- element set is 2^(n^2-n).
the sum of the elements divided by the number of elements is the average
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formula of diamond There is no straight relation at all
Henry Moseley discovered a relation between X-ray spectra and the atomic number of chemical elements.
If the universal set, U, has N elements then it has 2N subsets.
relation and function are number that combine with number and neqative number to .
make a table as I did below for the set {a,b,c} with 3 elements. A table with all n elements will represent all the possible relations on that set of n elements. We can use the table to find all types of relations, transitive, symmetric etc. | a | b | c | --+---+---+---+ a | * | | | b | | * | | c | | | * | The total number of relations is 2^(n^2) because for each a or b we can include or not include it so there are 2 possibilities and there are n^2 elements so 2^(n^2) total relations. A relation is reflexive if contains all pairs of the form {x,x) for any x in the set. So this is the diagonal of your box. THESE ARE FIXED! No, in reflexive relation we still can decide to include or not include any of the other elements. So we have n diagonal elements that are fixed and we subtract that from n^2 so we have 2^(n^2-n) If you do the same thing for symmetric relations you will get 2^(n(n+1)/2). We get this by picking all the squares on the diagonal and all the ones above it too.
This is a general tendence for an arrangement. Also it is a relation between atomic number and atomic weigths of chemical elements.
examples of number relation problems
the total no of reflexive relation on an n- element set is 2^(n^2-n).
Not generally. For light elements this relation is often approximately true, but for heavier elements, the gram atomic mass is more than two times the atomic number, as the ratio of neutrons to protons increases with increasing atomic mass.
the number of tuple in a relation is called the cordinality of a relation?
It can have any relation symbol - provided the relation is stated correctly.