Цикличные алгоритмы С++

 #include <cmath> 
#include <iomanip> 
#include <iostream> 
 
using namespace std; 
 
void f() 
{
  for (int i = 0; i < 34; ++i) cout << '=';
  cout << endl; 
} 
 
double u(double x) 
{
  return cos(x * x); 
} 
 
double v(double x) 
{
  double y = cos(x);
  return y * y; 
} 
 
int main() 
{
  double grad = M_PI / 180., x;
  f();
  cout << setprecision(4) << fixed
  << "   x    x, rad   cos(x²)   cos²(x)\n";
  f();
  for (int i = 0; i <= 180; i += 20)
  {
    x = i * grad;
    cout << setw(4) << i << setw(10) << x <<
    setw(10) << u(x) << setw(10) << v(x) << endl;
  }
  f(); 
}