# include iostream include math using namespace std double double return

 ``` 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 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67``` ```#include #include using namespace std; double f(double x) { return pow(x, 2) + 5 * pow(x, 3); // x^2 + 5 * x^3 } double find(double a, double b, double e, bool findMax) { double phi = (1 + sqrt(5)) / 2; double x1, x2, delta; while (b - a > e) { delta = (b - a) / phi(); x1 = b - delta; x2 = a + delta; if (findMax) { if (f(x1) <= f(x2)) { a = x1; } else { b = x2; } } else { if (f(x1) >= f(x2)) { a = x1; } else { b = x2; } } } return (a + b) / 2; } int main() { double a, b, e; int value; cout << "Enter a:"; cin >> a; cout << "Enter b:"; cin >> b; cout << "Enter epsilon:"; cin >> e; cout << "If u want find maximum enter 1 or enter any value for find minimum:"; cin >> value; double x = find(a, b, e, value == 1); cout << endl << "x = " << x << "; F(x) = " << f(x); } ```