# Mathematical Functions in Python | Set 4 (Special Functions and Constants)

Some of the mathematical functions are discussed in below set 1, set 2 and set 3
Mathematical Functions in Python | Set 1 (Numeric Functions)
Mathematical Functions in Python | Set 2 (Logarithmic and Power Functions)
Mathematical Functions in Python | Set 3 (Trigonometric and Angular Functions)

1. gamma() :- This function is used to return the gamma function of the argument.

 `# Python code to demonstrate the working of ` `# gamma() ` `  `  `# importing "math" for mathematical operations ` `import` `math ` ` `  `a ``=` `4` ` `  `# returning the gamma() of 4 ` `print` `(``"The gamma() of 4 is : "``, end``=``"") ` `print` `(math.gamma(a)) `

Output:

```The gamma() of 4 is : 6.0
```

2. pi :- This is an inbuilt constant that outputs the value of pi(3.141592).

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3. e :- This is an inbuilt constant that outputs the value of e(2.718281).

 `# Python code to demonstrate the working of ` `# const. pi and e ` `  `  `# importing "math" for mathematical operations ` `import` `math ` ` `  `# returning the value of const. pi ` `print` `(``"The value of const. pi is : "``, end``=``"") ` `print` `(math.pi) ` ` `  `# returning the value of const. e ` `print` `(``"The value of const. e is : "``, end``=``"") ` `print` `(math.e) `

Output:

```The value of const. pi is : 3.141592653589793
The value of const. e is : 2.718281828459045
```

4. inf :- This is a positive floating point infinity constant. -inf is used to denote the negative floating point infinity. This constant is defined in python 3.5 and above.

5. isinf() :- This function is used to check whether the value is an infinity or not.

6. nan :- This constant denotes “Not a number” in python. This constant is defined in python 3.5 and above.

7. isnan() :- This function returns true if the number is “nan” else returns false.

 `# Python code to demonstrate the working of ` `# inf, nan, isinf(), isnan() ` `  `  `# importing "math" for mathematical operations ` `import` `math ` ` `  `# checking if number is nan ` `if` `(math.isnan(math.nan)): ` `       ``print` `(``"The number is nan"``) ` `else` `: ``print` `(``"The number is not nan"``) ` ` `  `# checking if number is positive infinity ` `if` `(math.isinf(math.inf)): ` `       ``print` `(``"The number is positive infinity"``) ` `else` `: ``print` `(``"The number is not positive infinity"``) `

Output:

```The number is nan
The number is positive infinity
```

Python