runge_kutta.cpp

# include <stdio.h>

double f(double x,double y)
{
    return (x+y);
}

int main()
{
    double h=0.2;
    double x,y;
    x=0;
    y=1;
    double k1 = h * f(x,y);
    double k2 = h * f((x+h/2),(y+k1/2));
    double k3 = h * f((x+h/2),(y+k2/2));
    double k4 = h * f(x+h,y+k3);
    double k5 = 0.16 *(k1 + 2*k2 + 2*k3 + k4);
    printf("%f",k5);
}