private void button1_Click(object sender, EventArgs e)
{
try
{
double a, b, c; //係數
a = double.Parse(textBox1.Text);
b = double.Parse(textBox2.Text);
c = double.Parse(textBox3.Text);
double D, Re1, Re2, Im1, Im2; //Result 1, Result 2, 負數根
D = (b * b) - (4 * a * c); //判別式
if (D > 0) //判別式>0時
{
Re1 = ((-b + Math.Sqrt(D)) / (2 * a));
Re2 = ((-b - Math.Sqrt(D)) / (2 * a));
Im1 = 0;
Im2 = 0;
}
else if (D == 0.0) //判別式=0時
{
Re1 = -b / (2 * a);
Im1 = 0;
Re2 = Im2 = 0;
}
else //判別式<0時
{
Re1 = -b / (2 * a);
Re2 = Re1;
Im1 = Math.Sqrt(-D) / (2 * a);
Im2 = -Im1;
}
if (D == 0)
{
textBox4.Text = "x1 = " + Re1.ToString() + "+" + Im1.ToString() + "i";
}
else
{
textBox4.Text = "x1 = " + Re1.ToString() + "+" + Im1.ToString() + "i" + "\r\n" + "x2 = " + Re2.ToString() + "+" + Im2.ToString() + "i";
}
}
catch (Exception exception)
{
MessageBox.Show(exception.Message);
}
}
