Roots of Square Equation Calculator
This calculator finds the roots of a quadratic equation in the form ax² + bx + c = 0. It uses the quadratic formula to determine the solutions, whether they are real and distinct, real and equal, or complex.
How to Use This Calculator
To find the roots of a quadratic equation:
- Enter the coefficients a, b, and c in the input fields
- Click the "Calculate" button
- View the results showing the roots and discriminant
- Interpret the results based on the discriminant value
The calculator will display the roots and provide information about the nature of the solutions based on the discriminant.
The Quadratic Formula
The roots of a quadratic equation ax² + bx + c = 0 can be found using the quadratic formula:
x = [-b ± √(b² - 4ac)] / (2a)
Where:
- a, b, and c are coefficients of the quadratic equation
- √(b² - 4ac) is the discriminant
- The ± symbol indicates there are two possible solutions
The discriminant determines the nature of the roots:
- If discriminant > 0: Two distinct real roots
- If discriminant = 0: One real root (repeated)
- If discriminant < 0: Two complex conjugate roots
Understanding the Discriminant
The discriminant (D) is calculated as:
D = b² - 4ac
The discriminant provides important information about the roots:
- Positive discriminant: The equation has two real and distinct roots
- Zero discriminant: The equation has exactly one real root (a repeated root)
- Negative discriminant: The equation has no real roots, but two complex conjugate roots
Understanding the discriminant helps determine the nature of the solutions without actually calculating them.
Worked Examples
Example 1: Two Distinct Real Roots
Solve x² - 5x + 6 = 0
Using the quadratic formula:
x = [5 ± √(25 - 24)] / 2 = [5 ± 1] / 2
Solutions: x = 3 and x = 2
Example 2: One Real Root
Solve x² - 6x + 9 = 0
Using the quadratic formula:
x = [6 ± √(36 - 36)] / 2 = [6 ± 0] / 2
Solution: x = 3 (repeated root)
Example 3: Complex Roots
Solve x² + 2x + 5 = 0
Using the quadratic formula:
x = [-2 ± √(4 - 20)] / 2 = [-2 ± √(-16)] / 2
x = [-2 ± 4i] / 2 = -1 ± 2i
Solutions: x = -1 + 2i and x = -1 - 2i
Frequently Asked Questions
What is the quadratic formula used for?
The quadratic formula is used to find the roots of any quadratic equation in the form ax² + bx + c = 0. It provides exact solutions for the equation.
What does the discriminant tell me about the roots?
The discriminant (b² - 4ac) indicates the nature of the roots: positive for two distinct real roots, zero for one real root, and negative for two complex roots.
Can the quadratic formula be used for all quadratic equations?
Yes, the quadratic formula can be used for any quadratic equation as long as a ≠ 0. If a = 0, the equation is linear, not quadratic.
What if the discriminant is negative?
When the discriminant is negative, the equation has no real roots. The solutions will be complex numbers involving the imaginary unit i.
How accurate are the results from this calculator?
This calculator uses standard mathematical formulas and JavaScript's built-in math functions to provide accurate results. However, for critical applications, manual verification is recommended.