# exp() function for complex number in C++

• Last Updated : 31 Aug, 2022

The exp() function for complex number is defined in the complex header file. This function is the complex version of the exp() function. This function is used to calculate the base e exponential of a complex number z and returns the base-e exponential of complex number z. Syntax:

```template<class T> complex<T>
exp (const complex<T>& z );```

Parameter: This method takes a mandatory parameter z which represents the complex number. Return value: This function returns the base-e exponential of complex number z. Below programs illustrate the exp() function in C++: Example 1:-

## cpp

 `// c++ program to demonstrate``// example of exp() function.` `#include ``using` `namespace` `std;` `// driver program``int` `main()``{``    ``// initializing the complex: (-1.0+0.0i)``    ``complex<``double``> complexnumber(-1.0, 0.0);` `    ``// use of exp() function for complex number``    ``cout << ``"The exp of "``        ``<< complexnumber``        ``<< ``" is "``        ``<< ``exp``(complexnumber)``        ``<< endl;` `    ``return` `0;``}`

Output:

`The exp of (-1,0) is (0.367879,0)`

Time Complexity: O(1)

Auxiliary Space: O(1)

Example 2:-

## cpp

 `// c++ program to demonstrate``// example of exp() function.` `#include ``using` `namespace` `std;` `// driver program``int` `main()``{``    ``// initializing the complex: (0.0 + 1.0i)``    ``complex<``double``> complexnumber(0.0, 1.0);` `    ``// use of exp() function for complex number``    ``cout << ``"The exp of "``        ``<< complexnumber``        ``<< ``" is "``        ``<< ``exp``(complexnumber)``        ``<< endl;` `    ``return` `0;``}`

Output:

`The exp of (0,1) is (0.540302,0.841471)`

Time Complexity: O(1)

Auxiliary Space: O(1)

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