Создание глобальных переменных и функций в оконном приложении С++

double a, b, eps;
        int n;

#pragma once
 
namespace Проект1 {
 
    using namespace System;
    using namespace System::ComponentModel;
    using namespace System::Collections;
    using namespace System::Windows::Forms;
    using namespace System::Data;
    using namespace System::Drawing;
 
 
    /// <summary>
    /// Сводка для MyForm
    /// </summary>
    public ref class MyForm : public System::Windows::Forms::Form
    {
    public:
        MyForm(void)
        {
            InitializeComponent();
            //
            //TODO: добавьте код конструктора
            //
 
        }
 
    protected:
        /// <summary>
        /// Освободить все используемые ресурсы.
        /// </summary>
        ~MyForm()
        {
            if (components)
            {
                delete components;
            }
        }
    private: System::Windows::Forms::TextBox^  outTrap;
    protected: 
 
    private: System::Windows::Forms::TextBox^  outRect;
    protected: 
 
    private: System::Windows::Forms::TextBox^  inpN;
 
    private: System::Windows::Forms::TextBox^  inpB;
 
    private: System::Windows::Forms::TextBox^  inpA;
    private: System::Windows::Forms::TextBox^  outPar;
    private: System::Windows::Forms::TextBox^  outPar1;
 
 
 
    private: System::Windows::Forms::TextBox^  outTrap1;
 
    private: System::Windows::Forms::TextBox^  outRect1;
 
    private: System::Windows::Forms::TextBox^  eps;
 
    private: System::Windows::Forms::Button^  inputAll;
    private: System::Windows::Forms::Button^  Exit;
    private: System::Windows::Forms::Button^  inpPar1;
 
 
 
    private: System::Windows::Forms::Button^  inpPar;
 
    private: System::Windows::Forms::Button^  inpTrap;
 
    private: System::Windows::Forms::Button^  inpRect;
    private: System::Windows::Forms::Button^  inpEps;
    private: System::Windows::Forms::Button^  inpRect1;
    private: System::Windows::Forms::Button^  inpTrap1;
 
 
 
 
 
 
 
    private: System::Windows::Forms::Label^  label4;
    private: System::Windows::Forms::Label^  label5;
    private: System::Windows::Forms::Label^  label6;
    private: System::Windows::Forms::Label^  label7;
    private: System::Windows::Forms::Label^  label8;
 
    private:
        /// <summary>
        
        
/// Требуется переменная конструктора.
        /// </summary>
        System::ComponentModel::Container ^components;
 
#pragma region Windows Form Designer generated code
        /// <summary>
        /// Обязательный метод для поддержки конструктора - не изменяйте
        /// содержимое данного метода при помощи редактора кода.
        /// </summary>
        void InitializeComponent(void)
        {
            this->outTrap = (gcnew System::Windows::Forms::TextBox());
            this->outRect = (gcnew System::Windows::Forms::TextBox());
            this->inpN = (gcnew System::Windows::Forms::TextBox());
            this->inpB = (gcnew System::Windows::Forms::TextBox());
            this->inpA = (gcnew System::Windows::Forms::TextBox());
            this->outPar = (gcnew System::Windows::Forms::TextBox());
            this->outPar1 = (gcnew System::Windows::Forms::TextBox());
            this->outTrap1 = (gcnew System::Windows::Forms::TextBox());
            this->outRect1 = (gcnew System::Windows::Forms::TextBox());
            this->eps = (gcnew System::Windows::Forms::TextBox());
            this->inputAll = (gcnew System::Windows::Forms::Button());
            this->Exit = (gcnew System::Windows::Forms::Button());
            this->inpPar1 = (gcnew System::Windows::Forms::Button());
            this->inpPar = (gcnew System::Windows::Forms::Button());
            this->inpTrap = (gcnew System::Windows::Forms::Button());
            this->inpRect = (gcnew System::Windows::Forms::Button());
            this->inpEps = (gcnew System::Windows::Forms::Button());
            this->inpRect1 = (gcnew System::Windows::Forms::Button());
            this->inpTrap1 = (gcnew System::Windows::Forms::Button());
            this->label4 = (gcnew System::Windows::Forms::Label());
            this->label5 = (gcnew System::Windows::Forms::Label());
            this->label6 = (gcnew System::Windows::Forms::Label());
            this->label7 = (gcnew System::Windows::Forms::Label());
            this->label8 = (gcnew System::Windows::Forms::Label());
            this->SuspendLayout();
            // 
            // outTrap
            // 
            this->outTrap->Location = System::Drawing::Point(343, 253);
            this->outTrap->Name = L"outTrap";
            this->outTrap->Size = System::Drawing::Size(256, 20);
            this->outTrap->TabIndex = 1;
            this->outTrap->TextChanged += gcnew System::EventHandler(this, &MyForm::outTrap_TextChanged);
            // 
            // outRect
            // 
            this->outRect->Location = System::Drawing::Point(343, 170);
            this->outRect->Name = L"outRect";
            this->outRect->Size = System::Drawing::Size(256, 20);
            this->outRect->TabIndex = 2;
            this->outRect->TextChanged += gcnew System::EventHandler(this, &MyForm::outRect_TextChanged);
            // 
            // inpN
            // 
            this->inpN->Location = System::Drawing::Point(12, 253);
            this->inpN->Name = L"inpN";
            this->inpN->Size = System::Drawing::Size(256, 20);
            this->inpN->TabIndex = 3;
            this->inpN->Text = L"10";
            this->inpN->TextChanged += gcnew System::EventHandler(this, &MyForm::inpN_TextChanged);
            // 
            // inpB
            // 
            this->inpB->Location = System::Drawing::Point(12, 170);
            this->inpB->Name = L"inpB";
            this->inpB->Size = System::Drawing::Size(256, 20);
            this->inpB->TabIndex = 4;
            this->inpB->Text = L"2.0";
            this->inpB->TextChanged += gcnew System::EventHandler(this, &MyForm::inpB_TextChanged);
            // 
            // inpA
            // 
            this->inpA->Location = System::Drawing::Point(12, 80);
            this->inpA->Name = L"inpA";
            this->inpA->Size = System::Drawing::Size(256, 20);
            this->inpA->TabIndex = 5;
            this->inpA->Text = L"0.0";
            this->inpA->TextChanged += gcnew System::EventHandler(this, &MyForm::inpA_TextChanged);
            // 
            // outPar
            // 
            this->outPar->Location = System::Drawing::Point(343, 326);
            this->outPar->Name = L"outPar";
            this->outPar->Size = System::Drawing::Size(256, 20);
            this->outPar->TabIndex = 6;
            this->outPar->TextChanged += gcnew System::EventHandler(this, &MyForm::outPar_TextChanged);
            // 
            // outPar1
            // 
            this->outPar1->Location = System::Drawing::Point(674, 326);
            this->outPar1->Name = L"outPar1";
            this->outPar1->Size = System::Drawing::Size(256, 20);
            this->outPar1->TabIndex = 7;
            this->outPar1->TextChanged += gcnew System::EventHandler(this, &MyForm::outPar1_TextChanged);
            // 
            // outTrap1
            // 
            this->outTrap1->Location = System::Drawing::Point(674, 253);
            this->outTrap1->Name = L"outTrap1";
            this->outTrap1->Size = System::Drawing::Size(256, 20);
            this->outTrap1->TabIndex = 8;
            this->outTrap1->TextChanged += gcnew System::EventHandler(this, &MyForm::outTrap1_TextChanged);
            // 
            // outRect1
            // 
            this->outRect1->Location = System::Drawing::Point(674, 170);
            this->outRect1->Name = L"outRect1";
            this->outRect1->Size = System::Drawing::Size(256, 20);
            this->outRect1->TabIndex = 9;
            this->outRect1->TextChanged += gcnew System::EventHandler(this, &MyForm::outRect1_TextChanged);
            // 
            // eps
            // 
            this->eps->Location = System::Drawing::Point(674, 80);
            this->eps->Name = L"eps";
            this->eps->Size = System::Drawing::Size(256, 20);
            this->eps->TabIndex = 10;
            this->eps->Text = L"0.001";
            this->eps->TextChanged += gcnew System::EventHandler(this, &MyForm::eps_TextChanged);
            // 
            // inputAll
            // 
            this->inputAll->Location = System::Drawing::Point(12, 323);
            this->inputAll->Name = L"inputAll";
            this->inputAll->Size = System::Drawing::Size(256, 23);
            this->inputAll->TabIndex = 11;
            this->inputAll->Text = L"button1";
            this->inputAll->UseVisualStyleBackColor = true;
            this->inputAll->Click += gcnew System::EventHandler(this, &MyForm::inputAll_Click);
            // 
            .........
            // 
            // label8
            // 
            this->label8->AutoSize = true;
            this->label8->Location = System::Drawing::Point(9, 146);
            this->label8->Name = L"label8";
            this->label8->Size = System::Drawing::Size(173, 13);
            this->label8->TabIndex = 27;
            this->label8->Text = L"Верхний предел интегрирования";
            // 
            // MyForm
            // 
            this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
            this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
            this->ClientSize = System::Drawing::Size(942, 526);
            this->Controls->Add(this->label8);
            this->Controls->Add(this->label7);
            this->Controls->Add(this->label6);
            this->Controls->Add(this->label5);
            this->Controls->Add(this->label4);
            this->Controls->Add(this->inpTrap1);
            this->Controls->Add(this->inpRect1);
            this->Controls->Add(this->inpEps);
            this->Controls->Add(this->inpRect);
            this->Controls->Add(this->inpTrap);
            this->Controls->Add(this->inpPar);
            this->Controls->Add(this->inpPar1);
            this->Controls->Add(this->Exit);
            this->Controls->Add(this->inputAll);
            this->Controls->Add(this->eps);
            this->Controls->Add(this->outRect1);
            this->Controls->Add(this->outTrap1);
            this->Controls->Add(this->outPar1);
            this->Controls->Add(this->outPar);
            this->Controls->Add(this->inpA);
            this->Controls->Add(this->inpB);
            this->Controls->Add(this->inpN);
            this->Controls->Add(this->outRect);
            this->Controls->Add(this->outTrap);
            this->Name = L"MyForm";
            this->Text = L"MyForm";
            this->ResumeLayout(false);
            this->PerformLayout();
 
        }
 
#pragma endregion
 
        
private: System::Void inpA_TextChanged(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void inpB_TextChanged(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void inpN_TextChanged(System::Object^  sender, System::EventArgs^  e) {
         }
 
 
private: System::Void inputAll_Click(System::Object^  sender, System::EventArgs^  e) {
         a = Convert::ToDouble(inpA->Text);
         b = Convert::ToDouble(inpB->Text);
         n = Convert::ToInt32(inpN->Text);
         }
 
private: System::Void Exit_Click(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void inpRect_Click(System::Object^  sender, System::EventArgs^  e) {
         outRect->Text=Convert::ToString(Rect(n));
         }
private: System::Void outRect_TextChanged(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void inpTrap_Click(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void outTrap_TextChanged(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void inpPar_Click(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void outPar_TextChanged(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void eps_TextChanged(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void inpEps_Click(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void inpRect1_Click(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void outRect1_TextChanged(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void inpTrap1_Click(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void outTrap1_TextChanged(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void inpPar1_Click(System::Object^  sender, System::EventArgs^  e) {
         }
private: System::Void outPar1_TextChanged(System::Object^  sender, System::EventArgs^  e) {
         }
};
 
}

double a, b, eps;
        int n;
        double y(double x) {
            return x*x*x;}
        double Rect(int n) {
            double dx = (b - a) / n;
            double Sum = 0.0;
            double x = a;
            while (x<=b)
            {
                Sum += y(x);
                x += dx;
            }
            Sum *= dx;
            return Sum;}
        double Trap(int n) {
            double dx = (b - a) / n;
            double Sum = 0.0;
            double x = a+dx;
            while (x <= b-dx)
            {
                Sum += y(x);
                x += dx;
            }
            Sum += (y(a) + y(b)) / 2;
            Sum *= dx;
            return Sum;}
        double Par(int n) {
             double dx = (b - a) / n;
            double Sum = 0.0;
            double x = a+dx;
            while (x <= b-dx)
            {
                Sum += 4*y(x);
                x += 2*dx;
            }
            x = a + 2 * dx;
            while (x <= b - dx)
            {
                Sum += 2*y(x);
                x += 2*dx;
            }
            
            Sum += (y(a) + y(b));
            Sum *= dx/3;
            return Sum;}