W3School TIY Editor

#include <stdio.h> #include <math.h> int main() { const double E = 2.718281828; printf("%f\n", log(6.0)); printf("%f\n", log(E)); printf("%f\n", log(2.0)); printf("%f\n", log(1.0)); printf("%f\n", log(0.0)); printf("%f\n", log(-1.0)); return 0; }