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Download now on Google PlayFinite set: A set that has a finite number of elements is called finite set.

Example:

- The set of positive integers less than \(50\).
- The set of prime factors of \(275\).
- The set of vowels in alphabets.
- The set of keys on the laptop.

Infinite set: A set that has an infinite number of elements is called an infinite set.

Example:

- The set of rational numbers.
- The set of powers of \(2\).
- The set of multiples of \(6\).
- The collection of all even integers.

Set notation: A set is denoted by capital letters English alphabets \(A, B, C, D,...\)

Elements: Elements of the sets are denoted by small letters English alphabets \(a, b, c,...\)

Also, elements of the set should be written inside the curly brackets $\left\{\right\}$.

Important!

Suppose the element \(x\) lies in the set \(A\), then we can say that as \(x\) belongs to the set \(A\). That is, \(x\)$\in $\(A\).

Suppose the element \(x\) doesn't lie in the set \(A\), then we can say that \(x\) does not belong to the set \(A\). That is, \(x\)$\notin $ \(A\).

Example:

Consider the set $A\phantom{\rule{0.147em}{0ex}}=\left\{2,\phantom{\rule{0.147em}{0ex}}4,\phantom{\rule{0.147em}{0ex}}6,\phantom{\rule{0.147em}{0ex}}8,\phantom{\rule{0.147em}{0ex}}10\right\}$.

Here \(2\) is an element of \(A\). That is $2\in A$.

\(4\) is an element of \(A\). That is $4\in A$.

\(6\) is an element of \(A\). That is $6\in A$.

\(8\) is an element of \(A\). That is $8\in A$.

\(10\) is an element of \(A\). That is $10\in A$.

But the element \(5\) doesn't belong to \(A\). That is $5\notin A$.