int task01(double x0, int n, double* x, double* y, double* res);
int task02(double x0, int n, double* x, double* y, double* res);
int task03(double x0, int n, double* x, double* y, double* res);
double task04(double x0, int n, double* x, double* y, double* d, double* res);

double task05(double x0, double eps);
double task06(double x0, double eps);
double task07(double x0, double eps);
double task08(double x0, double exp);

double calculate_cos(double x0, double eps);
double calculate_sin(double x0, double eps);
double calculate_exp(double x0, double eps);
double calculate_log(double z, double eps);

double st_2(double x, int*c);