W3School TIY Editor

#include <stdio.h> #include <math.h> int main() { const double PI = 3.141592653589793; printf("%f\n", tan(3)); printf("%f\n", tan(-3)); printf("%f\n", tan(0)); printf("%f\n", tan(PI)); printf("%f\n", tan(PI / 2.0)); return 0; }