# log10() function for complex number in C++

• Difficulty Level : Easy
• Last Updated : 18 Aug, 2022

The log10() function for complex numbers is defined in the complex header file. This function is the complex version of the log10() function. This function is used to calculate the complex common log of a complex number z i.e with base 10 and returns the common log of complex number z.

Syntax:

```template<class T> complex<T>
log10 (const complex<T>& z );```

Parameter: This method takes a mandatory parameter z which represents the complex number.

Return value: This function returns the common log of the complex number z. Below programs illustrate the log10() function in C++:

Example 1:

## cpp

 `// C++ program to demonstrate``// example of log10() function.` `#include& lt; bits / stdc++.h & gt;``using` `namespace` `std;` `// driver program``int` `main()``{``    ``// initializing the complex: (-1.0+0.0i)``    ``complex& lt;``    ``double``& gt;``    ``complexnumber(-1.0, 0.0);` `    ``// use of log10() function for complex number``    ``cout& lt;``    ``<``    ``"``    ``The ``log10` `of& quot;``    ``<``    ``<``    ``complexnumber& lt;``    ``<``    ``"``    ``is& quot;``    ``<``    ``<``    ``log10``(complexnumber) & lt;``    ``<``    ``endl;` `    ``return` `0;``}`

Output:

`The log10 of (-1,0) is (0,1.36438)`

Time Complexity: O(1)

Auxiliary Space: O(1)

Example 2:

## cpp

 `// C++ program to demonstrate``// example of log10() function.` `#include& lt; bits / stdc++.h & gt;` `using` `namespace` `std;` `// Driver program``int` `main()``{``    ``// Initializing the complex: (-1.0 + -0.0i)``    ``complex& lt;``    ``double``& gt;``    ``complexnumber(-1.0, -0.0);` `    ``// use of log10() function for complex number``    ``cout& lt;``    ``<``    ``"``    ``The ``log10` `of& quot;``    ``<``    ``<``    ``complexnumber& lt;``    ``<``    ``"``    ``is& quot;``    ``<``    ``<``    ``log10``(complexnumber) & lt;``    ``<``    ``endl;` `    ``return` `0;``}`

Output:

`The log10 of (-1,-0) is (0,-1.36438)`

Time Complexity: O(1)

Auxiliary Space: O(1)

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