- A set is a well-defined collection of objects.
- If we want to find out the collection of five most renowned mathematicians of the world , then it is not well-defined, because the criterion for determining a mathematician as most renowned may vary from person to person. So this can't be a set.
- If `a` is an element of a set `A,` we say that “ a belongs to A” the Greek symbol ∈ (epsilon) is used to denote the phrase ‘belongs to’. Thus, we write `a ∈ A`. If ‘b’ is not an element of a set A, we write `b ∉ A` and read “b does not belong to A.
-Some Examples of set
N : the set of all natural numbers
Z : the set of all integers
Q : the set of all rational numbers
R : the set of real numbers
Z+ : the set of positive integers
Q+ : the set of positive rational numbers, and
R+ : the set of positive real numbers.
-The following points may be noted :
(i) If same element comes twice or more time in set, then its consider once at final set.
(ii) Sets are usually denoted by capital letters `A, B, C, X, Y, Z`, etc.
(iii) The elements of a set are represented by small letters `a, b, c, x, y, z`, etc.
- A set is a well-defined collection of objects.
- If we want to find out the collection of five most renowned mathematicians of the world , then it is not well-defined, because the criterion for determining a mathematician as most renowned may vary from person to person. So this can't be a set.
- If `a` is an element of a set `A,` we say that “ a belongs to A” the Greek symbol ∈ (epsilon) is used to denote the phrase ‘belongs to’. Thus, we write `a ∈ A`. If ‘b’ is not an element of a set A, we write `b ∉ A` and read “b does not belong to A.
-Some Examples of set
N : the set of all natural numbers
Z : the set of all integers
Q : the set of all rational numbers
R : the set of real numbers
Z+ : the set of positive integers
Q+ : the set of positive rational numbers, and
R+ : the set of positive real numbers.
-The following points may be noted :
(i) If same element comes twice or more time in set, then its consider once at final set.
(ii) Sets are usually denoted by capital letters `A, B, C, X, Y, Z`, etc.
(iii) The elements of a set are represented by small letters `a, b, c, x, y, z`, etc.