The Quadratic Formula
Every quadratic equation can be solved using the quadratic formula:
x = (-b ± √(b² - 4ac)) / 2a
The Discriminant (D)
The expression inside the square root, b² - 4ac, is known as the discriminant. It tells us the nature of the roots:
- D > 0: Two distinct real roots.
- D = 0: Two equal real roots (one root).
- D < 0: Two complex (imaginary) roots.