#include <cmath>

// 1.1     e^(x - 1) - x^3 - x
double function_1(double x)
{
  return std::exp(x - 1) - std::pow(x, 3) - x;
}


// 1.2     1 / (3 + sin(3.6x))
double function_2(double x)
{
  return 1 / (3 + std::sin(3.6 * x));  
}


// 1.3     arccos(x) - √(1 - 0.3x^3)
double function_3(double x)
{
  return std::acos(x) - std::sqrt(1 - 0.3 * std::pow(x, 3));
}


// 1.9      0.25x^3 + x - 2 
double function_9(double x)
{
  return 0.25 * std::pow(x, 3) + x - 2;
}