Построение графика по функции

double nachalo, conets; int numbj;
private: delegate double Function(double);
private: double f(double x) {
return (numbj % 10) * x * Math::Sin(x) - (int)(numbj / 10) * x * Math::Cos(x);
}
private:double X, Y1, Y2, Y;

private: System::Void button1_Click(System::Object^ sender, System::EventArgs^ e) {
int pw = pictureBox1->Width, ph = pictureBox1->Height;
Function^ f = gcnew Function(this, &MyForm::f);
conets = Convert::ToDouble(textBox1->Text);
nachalo = Convert::ToDouble(textBox2->Text);
numbj = Convert::ToDouble(textBox3->Text);

X = (conets - (-1 * (nachalo))) / pw;
Y1 = Y2 = f(nachalo);

for (double x = (-1 * (nachalo)); x <= conets; x += X) {
double y = f(x);
if (y > Y2) Y2 = y;
if (y < Y1) Y1 = y;
}

Y = (Y2 - Y1) / ph;
double x_coff = pw / (conets - (-1 * (nachalo))), y_coff = ph / (Y2 - Y1);

Bitmap^ img = gcnew Bitmap(pw, ph);
Graphics^ g = Graphics::FromImage(img);

int mx = -1 * (-1 * (nachalo)) * x_coff, my = -Y1 * y_coff;
g->DrawLine(Pens::Red, mx, 0, mx, ph);
g->DrawLine(Pens::Red, 0, my, pw, my);

System::Collections::Generic::List <PointF>^ Points = gcnew System::Collections::Generic::List <PointF>();
double x = (-1 * (nachalo)), y;
while (x <= conets) {
y = f(x);
Points->Add(PointF((x - (-1 * (nachalo))) * x_coff, (Y2 - y) * y_coff));
x += X;
}
g->DrawLines(Pens::Pink, Points->ToArray());
this->pictureBox1->Image = img;

label5->Text = "f(x)=" + numbj + "%10 * x * Sin(x) - " + numbj + "/10 * x * Cos(x)";
}