What's a fast way to determine the type of roots of a quadratic function?

Question

Hint: it has to do with the standard form of the quadratic formula but it does not require the quadratic formula.

Answer 1

ax² + bx + c = 0

Find the discriminant:

D = b² - 4ac

If D = 0, there is a real root of multiplicity 2.

If D > 0, there are 2 different real roots.

If D < 0, there are 2 different complex roots.