#include<stdio.h>
#include<conio.h>
#include<iostream.h>
#include<math.h>
void main()
{
double n,e;
clrscr();
cout<<"Enter any number = ";
cin>>n;
e=log(n);
cout<<"\nlog("<<n<<") = "<<e;
getch();
}
///////////////////////////////////////////////////////////////////////////
Copy & paste this code in your TC & run, then you will get output.......
If you have any problem please comment below.........