Quadratic Formula Calculator

Written by:
PK

Below is a quadratic formula calculator that solves quadratic equations in the form ax² + bx + c = 0. Enter your coefficients and the tool finds the roots (solutions).

Quadratic Formula Calculator

Using the quadratic formula calculator

Enter the coefficients a, b, and c from your quadratic equation ax² + bx + c = 0. The calculator solves in real-time, displaying:

  • Both roots (x₁ and x₂)
  • The discriminant value and what it means
  • Complex solutions when the discriminant is negative
  • The vertex of the parabola

What is the quadratic formula?

The quadratic formula solves any quadratic equation of the form ax² + bx + c = 0:

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

The expression under the square root, b² - 4ac, is called the discriminant. It determines the nature of the solutions:

  • Positive discriminant: Two distinct real solutions
  • Zero discriminant: One repeated real solution
  • Negative discriminant: Two complex (imaginary) solutions

Example calculation

For x² - 5x + 6 = 0 (a=1, b=-5, c=6):

\text{Discriminant} = (-5)^2 - 4(1)(6) = 25 - 24 = 1
x = \frac{5 \pm \sqrt{1}}{2} = \frac{5 \pm 1}{2}

Solutions: x = 3 and x = 2

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PK

PK started DQYDJ in 2009 to research and discuss finance and investing and help answer financial questions. He's expanded DQYDJ to build visualizations, calculators, and interactive tools.

PK lives in New Hampshire with his wife, kids, and dog.

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