INsf1h

#include <iostream>
#include <cmath>
#include <iomanip>

using namespace std;
#define eps 0.0001
// sin(x1 + x2) - 1.2 * x1 - 0.1 = 0
// x1^2 + x2 ^ 2 - 1 = 0
// x2 = arcsin(1.2 * x1 + 0.1)
// x2 = sqrt(1 - x1 ^ 2)
// x1 - [0, 1]; x2 - [0, 1]
// начальное приближение x - [0, 1]

double function1(double x, double y)
{
    //return sin(x + y) - 1.2 * x - 0.1;
    return cos(x) + y - 1.5;
}

double function2(double x, double y)
{
    //return x * x + y * y - 1;
    return 2 * x - sin(y - 0.5) - 1;
}

double func11(double x, double y)
{
    //return cos(x + y) - 1.2;
    return -sin(x);
}

double func12(double x, double y)
{
    //return cos(x + y);
    return 1;
}

double func21(double x, double y)
{
    //return 2 * x;
    return 2;
}

double func22(double x, double y)
{
    //return 2 * y;
    return -cos(y - 0.5);
}

void ober_matr(double a[2][2])
{
    double det, aa;
    det = a[0][0] * a[1][1] - a[0][1] * a[1][0];
    aa = a[0][0];
    a[0][0] = a[1][1] / det;
    a[1][1] = aa / det;
    aa = a[0][1];
    a[0][1] = -a[0][1] / det;
    a[1][0] = -a[1][0] / det;
}

void nuton(double x, double y)
{
    int i = 1;
    double a[2][2], dx, dy, b[2], norm;
    do
    {
        a[0][0] = func11(x, y);
        a[0][1] = func12(x, y);
        a[1][0] = func21(x, y);
        a[1][1] = func22(x, y);
        ober_matr(a);
        dx = -a[0][0] * function1(x, y) + -a[0][1] * function2(x, y);
        dy = -a[1][0] * function1(x, y) + -a[1][1] * function2(x, y);
        x = x + dx;
        y = y + dy;
        b[0] = function1(x, y);
        b[1] = function2(x, y);
        norm = sqrt(b[0] * b[0] + b[1] * b[1]);
        i++;
    } while (norm >= eps);
    cout << x << endl << y << endl;
    cout << i << " итераций" << endl;
}
void main()
{
    setlocale(LC_ALL, "RU");
    double x, y;
    cout << "x = ";
    cin >> x;
    cout << "y = ";
    cin >> y;
    nuton(x, y);
    cout << endl;
    system("PAUSE");
}