#include <cmath>

const double PI = 3.141592;

double declinaisonSoleil(unsigned int day) {
    return asin(0.398 * sin(0.0171915 * day - 1.3962634));
}

double dureeInsolation(
    double latitude, double declinaison
) {
    return 24/PI * acos(-tan(latitude) * tan(declinaison));
}

double deg2Rad(double degree) {
    return degree * PI / 180;
}