Cubic Equation Calculator
Solutions:
Solution for Cubical Equation
Use this calculator to solve polynomial equations with an order of 3 such as ax3 + bx2 + cx + d = 0 for x including complex solutions.
Enter positive or negative values for a, b, c and d and the calculator will find all solutions for x. Enter 0 if that term is not present in your cubic equation.
There are either one or three possible real root solutions for x for any cubic equation. You may have only two distinct solutions as in the case x = 1, x = 5, x = 5, however there are still three real roots.
What is a Cubic Equation?
A cubic equation is an algebraic equation with a degree of 3. This means that the highest exponent in the equation is 3. Written in standard form, where a ≠ 0 a cubic equation looks like this:
a.x3 + b.x2 + c.x + d = 0 ……………………………………eq.
The b, c or d terms may be missing from the equation, or the a term might be 1. As long as there is an ax3 value you have a cubic equation.
How to Solve a Cubic Equation
There are multiple ways to solve cubic equations. The method you use depends on your equation. Check the guidance below for the best way to solve your cubic equation.
Methods to Solve Cubic Equations That Do Not Have a Constant, d
If your equation does not have a constant d you can factor out the x, so one of your answers is x = 0. Then you can use one of these methods to solve the resulting quadratic equation, which is simply an equation of degree 2:
- Factor the resulting quadratic equation
- Solve the resulting quadratic equation by Completing the Square
- Solve the resulting quadratic equation with the Quadratic Formula