梯形方法(数值分析 c++)

#include <iostream>

#include <iomanip>

using namespace std;

int main()

{

double f(double X,double Y);

double x,x1,y,y1,k,h=0.02;

cout<<setw(5)<<"k"<<setw(15)<<"xk"<<setw(15)<<"yk"<<endl;

for(k=0;k<=5;k++)

{

if(k==0) {x=0;y=1;}

else

{

y1=y+h*f(x,y);

x1=x+h;

y=y+h*(f(x,y)+f(x1,y1))/2;

x+=h;

}

cout<<setw(5)<<k<<setw(15)<<x<<setw(15)<<y<<endl;

}

return 0;

}

double f(double X,double Y)

{

double y;

y=-0.9*Y/(1+2*X);

return (y);

}