Question

The discriminant of the quadratic equation ax² + bx + c = 0, a ≠ 0 is given by:

Options

• b² – 2ac

• b² – ac

• b² – 4ac

• none of these

Answer 1

b² – 4ac

Explanation:

The discriminant D is the expression under the square root in the quadratic formula, D = b² – 4ac and it determines the nature of the roots D > 0: two distinct real roots; D = 0: one repeated real root; D < 0: complex roots.