{{keywords>wiki library source code example reference}}
===== log10 =====
<code cpp>
    double log10(double);
</code>
base-10 logarithm of a number

===== cpp Sourcecode Example =====
<code cpp>     
#include <iostream> /* including standard library */
#include <cmath> /* including math library */

using namespace std;
int main ( void )
{
    double x;
    x = log10(42000);
    
    //cout.setf(ios::fixed, ios::floatfield);
    cout.precision(8);

    cout << "The log10 of 42000 is " << x << endl;
    return 0;
}
</code>

==== output ====
     The log10 of 42000 is 4.6232493