double x1[2]; 
Fct(t, h, x, f); 
x[0] = x1[0]; 
x[1] = x1[1]; 
x1[0] = x[0] + h*f[0]; 
x1[1] = x[1] + h*f[1]; 
} 
 
 
fclose(fp); 
        return 0; 
} 
 
void Euler(double t, double h, double* x, double* f) 
{ 
 
 
 
 
 
 
 
 
 
 
} 
 
void rnge_kutta2(double t, double h, double* x, double* f) 
{ 
        double k1[2],k2[2],x1[2]; 
 
        Fct(t,h,x,f); 
        k1[0]=f[0]; 
        k1[1]=f[1]; 
 
        x1[0]=x[0]+h*k1[0]; 
        x1[1]=x[1]+h*k1[1]; 
 
        Fct(t+h/2,h,x1,f); 
        k2[0]=f[0]; 
        k2[1]=f[1]; 
 
        x1[0]=x[0]+h/2*(k2[0]+k1[0]); 
        x1[1]=x[1]+h/2*(k2[1]+k1[1]); 
 
        x[0] = x1[0]; 
 
x[1] = x1[1]; 
} 
 
void rnge_kutta4(double t, double h, double* x, double* f) 
{ 
        double k1[2],k2[2],k3[2],k4[2],x1[2]; 
 
        Fct(t,h,x,f); 
        k1[0]=f[0]; 
        k1[1]=f[1]; 
 
        x1[0]=x[0]+h/2*k1[0]; 
        x1[1]=x[1]+h/2*k1[1]; 
 
        Fct(t+h/2,h,x1,f); 
        k2[0]=f[0]; 
        k2[1]=f[1]; 
 
        x1[0]=x[0]+h/2*k2[0]; 
        x1[1]=x[1]+h/2*k2[1]; 
 
        Fct(t+h/2,h,x1,f); 
        k3[0]=f[0]; 
        k3[1]=f[1]; 
 
        x1[0]=x[0]+h*k3[0]; 
        x1[1]=x[1]+h*k3[1]; 
 
        Fct(t+h,h,x1,f); 
        k4[0]=f[0]; 
        k4[1]=f[1]; 
 
        x1[0]=x[0]+h/6*(k1[0]+2*k2[0]+2*k3[0]+k4[0]); 
        x1[1]=x[1]+h/6*(k1[1]+2*k2[1]+2*k3[1]+k4[1]); 
 
        x[0]=x1[0]; 
        x[1]=x1[1]; 
} 
 
void Fct(double t, double h, double* x, double* f) 
{ 
 
        double den; 
 
 
 
} 
 
double lagrange(double* x) 
{ 
double g = 9.81; 
f[0] = x[1]; 
den = lagrange(x); 
f[1] = -5*g+0.5*0.02*3.14*0.05*0.05*x[1]*x[1]*den; 
double p, md1 = 0; 
double gd[9] = { 0.0, 1000, 3000, 5000, 7000, 9000, 11000, 15000, 20000}; 
double md[9] = { 1.225, 1.112, 0.909, 0.736, 0.589, 0.466, 0.364, 0.194, 0.088}; 
if (i != j) { 
 
} 
p = p * ((x[0] - gd[j]) / (gd[i] - gd[j])); 
        int n=9; 
        int i, j; 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
} 
for (i = 0; i < n; i++) { 
 
 
 
 
 
 
p = 1; 
for (j = 0; j < n; j++) { 
 
 
 
} 
  md1 = md1 + p * md[i]; 
} 
return md1;