W3School TIY Editor

#include <stdio.h> #include <math.h> int main() { printf("%f\n", atan2(0.5, 0.5)); printf("%f\n", atan2(-0.5, -0.5)); printf("%f\n", atan2(5, 5)); printf("%f\n", atan2(10, 20)); printf("%f\n", atan2(5, -5)); printf("%f\n", atan2(-10, 10)); return 0; }