# methods - lab6 - all

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46``` ```public class Marina_lab6 { static int size = 9; public static double f(double x, double a, double b) { return 1 / (a*x + b); } public static double SKU(double a, double b, double[] x, double[] y) { double sum = 0.0; for (int i = 0; i < size; i++) { sum += (a * x[i] + b - y[i]) * (a * x[i] + b - y[i]); } return Math.sqrt(sum); } public static double[] reverseY(double[] y) { for (int i = 0; i < size; i++) { y[i] = 1 / y[i]; } return y; } public static void main(String args[]) { double x[] = {1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0}; double y[] = {2.07, 2.41, 1.77, 1.98, 2.24, 2.73, 2.91, 2.56, 3.07}; double a = 0, b = 0, c = 0, d = size, e = 0, f = 0; double A, B; y = reverseY(y); for(int i = 0; i < size; i++) { a += x[i] * x[i]; b += x[i]; f += x[i] * y[i]; e += y[i]; } c = b; B = (a*e - c*f) / (a*d - b*c); A = (f - B*b) / a; System.out.println("f(x) = 1 / (" + A + "*x + " + B + ")"); System.out.println("SKU = " + SKU(A, B, x, y)); System.out.println("SKU for appr function f(x) = 0.5x + 1: SKU = " + SKU(0.5, 1, x, y)); } } ```