Quadratic Equation Solver

Updated for 2026

Quick Answer

Solve any quadratic equation instantly. Get the roots (x-intercepts), the discriminant, and step-by-step formatting to help you double-check your algebra homework. Use typical values to get quick results.

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Quadratic Equation Solver

Last updated: March 26, 2026

Check your algebra homework instantly with our Quadratic Equation Solver. Enter your aa, bb, and cc coefficients to find the exact roots, the discriminant, and whether the roots are real or complex.

The Quadratic Formula

A standard quadratic equation is written in the form:

ax2+bx+c=0ax^2 + bx + c = 0

To find the roots (the points where the parabola crosses the x-axis), we use the famous quadratic formula:

x=b±b24ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}

The Discriminant (Δ\Delta)

The part of the formula under the square root is called the discriminant. It tells you exactly what kind of roots the equation has:

Δ=b24ac\Delta = b^2 - 4ac

Understanding the Results

By analyzing the discriminant (Δ\Delta), you can check if your homework answers make sense:

  • If Δ>0\Delta > 0: The equation has two distinct real roots. The parabola crosses the x-axis at two different points.
  • If Δ=0\Delta = 0: The equation has one repeated real root. The vertex of the parabola rests exactly on the x-axis.
  • If Δ<0\Delta < 0: The equation has two complex (imaginary) roots. The parabola never touches the x-axis. Complex roots are usually written in the format a+bia + bi.