double f0(double x);
double f1(double x);
double f2(double x);
double f3(double x);
double f4(double x);
double f5(double x);
double f6(double x);

double df0(double x);
double df1(double x);
double df2(double x);
double df3(double x);
double df4(double x);
double df5(double x);
double df6(double x);

double f7(double x); // УДАЛИТЬ!!!

int c(void);