irrational number, any real number that cannot be expressed as the quotient of two integers.
Any number that can be written as a fraction with integers is called a rational number . For example, 17 and −34 are rational numbers. (Note that there is more than one way to write the same rational number as a ratio of integers.
1st Is rational
2nd one is irrational
3rd is irrational
4th is rational
