Cubic Equation Calculator
Solve cubic equations of the form ax^3+bx^2+cx+d=0.
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Introduction
Cubic Equation Calculator — Solve cubic equations of the form ax^3+bx^2+cx+d=0. Enter a, b, c, d to get an instant, accurate result.
Formula
Solves ax³+bx²+cx+d=0 using Cardano's method: the equation is depressed to t³+pt+q=0, and the discriminant (q²/4 + p³/27) determines whether there is one real root or three.
Step-by-step
- Enter the a.
- Enter the b.
- Enter the c.
- Enter the d.
- Click Calculate to see your result instantly.
Real-world example
Example: With a = 1, b = -6, c = 11, d = -6, the Cubic Equation Calculator gives Roots: 3, 1, 2.
Frequently Asked Questions
How many roots does a cubic have?
Always three (counting multiplicity and complex roots), but this calculator returns one or three real roots depending on the discriminant.
What if a = 0?
That's not a true cubic equation — the calculator requires a nonzero leading coefficient.
What inputs does the Cubic Equation Calculator need?
You'll need to provide: a, b, c, d. All fields use sensible defaults, so you can see a working example immediately and then adjust the values to match your own numbers.
How accurate is the Cubic Equation Calculator?
The Cubic Equation Calculator applies the formula exactly as calculated — Solves ax³+bx²+cx+d=0 using Cardano's method: the equation is depressed to t³+pt+q=0, and the discriminant (q²/4 + p³/27) determines whether there is one real root or three. — so results are precise for the inputs you provide. Accuracy depends on entering correct, realistic input values.
Is the Cubic Equation Calculator free to use?
Yes, the Cubic Equation Calculator is completely free, requires no signup, and runs instantly in your browser.
About the Cubic Equation Calculator
The Cubic Equation Calculator uses a real, verifiable formula — Solves ax³+bx²+cx+d=0 using Cardano's method: the equation is depressed to t³+pt+q=0, and the discriminant (q²/4 + p³/27) determines whether there is one real root or three. — so results are accurate every time, not an approximation.