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Quadratic - Transformations Roots and The Discriminant Calculator

Reviewed by Calculator Editorial Team

Quadratic equations are fundamental in algebra and appear in many real-world applications. This guide explains quadratic transformations, how to find roots, and the significance of the discriminant. The calculator on this page helps you analyze quadratic functions, visualize transformations, and understand the relationship between coefficients and roots.

What is a Quadratic Equation?

A quadratic equation is a second-degree polynomial equation in the form:

ax² + bx + c = 0

Where:

  • a is the coefficient of x² (must not be zero)
  • b is the coefficient of x
  • c is the constant term

Quadratic equations can represent parabolic curves when graphed. The shape of the parabola depends on the coefficients a, b, and c.

Roots and the Discriminant

The roots of a quadratic equation are the values of x that satisfy the equation. The discriminant (D) determines the nature of the roots:

D = b² - 4ac

The discriminant provides important information about the roots:

  • D > 0: Two distinct real roots
  • D = 0: One real root (repeated)
  • D < 0: Two complex conjugate roots

The roots can be calculated using the quadratic formula:

x = [-b ± √(b² - 4ac)] / (2a)

The discriminant also affects the vertex of the parabola. The x-coordinate of the vertex is given by -b/(2a).

Quadratic Transformations

Quadratic functions can be transformed by shifting, stretching, and reflecting. The general form of a transformed quadratic is:

y = a(x - h)² + k

Where:

  • (h, k) is the vertex of the parabola
  • a determines the parabola's width and direction

Common transformations include:

  • Horizontal shifts: Changing h moves the parabola left or right
  • Vertical shifts: Changing k moves the parabola up or down
  • Vertical stretching/compression: Changing a affects the parabola's width
  • Reflection: A negative a reflects the parabola across the x-axis

These transformations affect both the roots and the vertex of the quadratic function.

How to Use This Calculator

This calculator helps you analyze quadratic equations by:

  1. Entering coefficients a, b, and c
  2. Viewing the discriminant and roots
  3. Visualizing the quadratic function
  4. Understanding transformations

For example, if you enter a=1, b=-3, and c=2, the calculator will show:

  • Discriminant: 1
  • Roots: x=1 and x=2
  • Vertex at (1.5, -0.25)

The chart visualizes the quadratic function y = x² - 3x + 2.

FAQ

What does the discriminant tell me about the roots?
The discriminant indicates whether the quadratic equation has two distinct real roots, one repeated real root, or two complex conjugate roots.
How do I find the vertex of a quadratic function?
The x-coordinate of the vertex is -b/(2a). The y-coordinate can be found by substituting x = -b/(2a) into the quadratic equation.
What happens when a=0 in a quadratic equation?
When a=0, the equation is no longer quadratic but linear. The discriminant formula still applies, but the interpretation changes.