- The program below perfectly solves the Cubic Equation of the form Ax^3 + Bx^2 + Cx + D.
- The flawless code is written in .Net C#.
- The real and imaginary roots are separated by black and red colors respectively.
- Simply update the value of variables A, B, C and D to see the answers i.e. the solution of the equation.
- To find the 2 roots, solution of a Quadratic equation please visit here.
- This code is written by Code-Kings exclusively for YOU! Please like us wherever possible and show some love in return!
namespace
WindowsFormsApplication1
{
public partial class Form1 : Form
{
public
Form1()
{
InitializeComponent();
}
private
void CubicCalculations()
{
try
{
double
a = double.Parse(TCubA.Text);
double
b = double.Parse(TCubB.Text);
double
c = double.Parse(TCubC.Text);
double
d = double.Parse(TCubD.Text);
double
f = (((3 * c) / a) - ((b * b) / (a * a))) / 3;
string
f2 = f.ToString();
double
g = (((2 * (Math.Pow(b, 3))) / (Math.Pow(a, 3))) - ((9 * b * c) / (Math.Pow(a, 2))) + ((27 * d) / a)) / 27;
string
g2 = g.ToString();
double
h = ((Math.Pow(g, 2)) / 4) + ((Math.Pow(f, 3)) / 27);
string
h2 = h.ToString();
if
(h <= 0)
{
double
i = (((Math.Pow(g, 2)) / 4) - h);
double
i2 = Math.Pow(i, 0.5);
string
i3 = i2.ToString();
double
j = (Math.Pow(i2,
0.333333333333333333333333));
string
j2 = j.ToString();
double
k = ((Math.Acos(0 - (g / (2 * i2)))));
string
k2 = k.ToString();
double
l = (j * (0 - 1));
string
l2 = l.ToString();
double
m = ((Math.Cos(k / 3)));
string
m2 = m.ToString();
double
n = ((Math.Pow(3, 0.5)) * Math.Sin(k / 3));
string
n2 = n.ToString();
double
p = ((b / (3 * a)) * (0 - 1));
string
p2 = p.ToString();
double
x = ((2 * j) * (Math.Cos(k / 3)) - (b / (3 *
a)));
string
x2 = x.ToString();
TCubFR.Text = x2;
double
y = (l * (m + n) + p);
string
y2 = y.ToString();
TCubSR.Text = y2;
double
z = (l * (m - n) + p);
string
z2 = z.ToString();
TCubTR.Text = z2;
}
if
(h > 0)
{
double
u = 0 - g;
double
r = (u / 2) + (Math.Pow(h, 0.5));
string
r2 = r.ToString();
if
(r >= 0)
{
double s6 = (Math.Pow(r,
0.333333333333333333333333333));
double s8 = s6;
string s9 = s8.ToString();
double t8 = (u / 2) - (Math.Pow(h,
0.5));
string t9 = t8.ToString();
double help8 = (1.0 / 3);
string help9 = help8.ToString();
if (t8 < 0)
{
double v7 = (Math.Pow((0
- t8), 0.33333333333333333333));
double v8 = (v7);
string v9 = v8.ToString();
double x3 = (s8 - v8) - (b / (3 * a));
string x4 = x3.ToString();
TCubFR.Text = x4;
double y3 = ((0 - (s8 - v8)) / 2) - (b / (3 * a));
double y4 = ((s8 + v8) * (Math.Sqrt(3)
/ 2));
string y6 = y3.ToString();
string y7 = y4.ToString();
TCubSR.Text = y6 + " + " + y7 + "i";
double z3 = ((0 - (s8 - v8)) / 2) - (b / (3 * a));
double z4 = ((s8 + v8) * (Math.Sqrt(3))
/ 2);
string z6 = z3.ToString();
string z7 = z4.ToString();
TCubTR.Text = z6 + " - " + z7 + "i";
}
if
(t8 >= 0)
{
double v6 = (Math.Pow((0
- (0 - t8)), 0.33333333333333333333));
double v5 = (v6);
string v4 = v5.ToString();
double x3 = (s8 + v5) - (b / (3 * a));
string x4 = x3.ToString();
TCubFR.Text = x4;
double
y3 = ((0 - (s8 + v5)) / 2) - (b / (3 * a));
double y4 = ((s8 - v5) * (Math.Sqrt(3)
/ 2));
string y6 = y3.ToString();
string y7 = y4.ToString();
TCubSR.Text = y6 + " + " + y7 + "i";
double z3 = ((0 - (s8 + v5)) / 2) - (b / (3 * a));
double z4 = ((s8 - v5) * (Math.Sqrt(3))
/ 2);
string z6 = z3.ToString();
string z7 = z4.ToString();
TCubTR.Text = z6 + " - " + z7 + "i";
}
}
if
(r < 0)
{
double s3 = (Math.Pow((0 - r),
0.333333333333333333333333333));
double s = (0 - s3);
string s2 = s.ToString();
double t = (u / 2) - (Math.Pow(h,
0.5));
string t2 = t.ToString();
double help = (1.0 / 3);
string help2 = help.ToString();
if (t < 0)
{
double v = (Math.Pow((0
- t), 0.33333333333333333333));
double v2 = (v);
string v3 = v2.ToString();
double x3 = (s - v2) - (b / (3 * a));
string x4 = x3.ToString();
TCubFR.Text = x4;
double y3 = ((0 - (s - v2)) / 2) - (b / (3 * a));
double y4 = ((s + v2) * (Math.Sqrt(3)
/ 2));
string y6 = y3.ToString();
string y7 = y4.ToString();
TCubSR.Text = y6 + " + " + y7 + "i";
double z3 = ((0 - (s - v2)) / 2) - (b / (3 * a));
double z4 = ((s + v2) * (Math.Sqrt(3))
/ 2);
string z6 = z3.ToString();
string z7 = z4.ToString();
TCubTR.Text = z6 + " - " + z7 + "i";
}
if (t >= 0)
{
double v = (Math.Pow((0
- (0 - t)), 0.33333333333333333333));
double v2 = (v);
string v3 = v2.ToString();
double x3 = (s + v2) - (b / (3 * a));
string x4 = x3.ToString();
TCubFR.Text = x4;
double y3 = ((0 - (s + v2)) / 2) - (b / (3 * a));
double y4 = ((s - v2) * (Math.Sqrt(3)
/ 2));
string y6 = y3.ToString();
string y7 = y4.ToString();
TCubSR.Text = y6 + " + " + y7 + "i";
double z3 = ((0 - (s + v2)) / 2) - (b / (3 * a));
double z4 = ((s - v2) * (Math.Sqrt(3))
/ 2);
string z6 = z3.ToString();
string z7 = z4.ToString();
TCubTR.Text = z6 + " - " + z7 + "i";
}
}
}
if
(h == 0 && f == 0 && g == 0)
{
double
x5 = ((Math.Pow((d / a),
0.3333333333333333333))) * (0 - 1);
string
x6 = x5.ToString();
TCubFR.Text = x6;
TCubSR.Text = x6;
TCubTR.Text = x6;
}
}
catch
{ }
}
private
void TCubA_TextChanged(object
sender, EventArgs e)
{
CubicCalculations();
}
private
void TCubB_TextChanged(object
sender, EventArgs e)
{
CubicCalculations();
}
private
void TCubC_TextChanged(object
sender, EventArgs e)
{
CubicCalculations();
}
private
void TCubD_TextChanged(object
sender, EventArgs e)
{
CubicCalculations();
}
private
void TCubFR_TextChanged(object sender, EventArgs e)
{
if
(TCubFR.Text.Contains("i"))
{
TCubFR.ForeColor = Color.Red;
}
else
{
TCubFR.ForeColor = Color.Black;
}
}
private
void TCubSR_TextChanged(object sender, EventArgs e)
{
if
(TCubSR.Text.Contains("i"))
{
TCubSR.ForeColor = Color.Red;
}
else
{
TCubSR.ForeColor = Color.Black;
}
}
private
void TCubTR_TextChanged(object sender, EventArgs e)
{
if
(TCubTR.Text.Contains("i"))
{
TCubTR.ForeColor = Color.Red;
}
else
{
TCubTR.ForeColor = Color.Black;
}
}
}
}
