Solve any quadratic equation using the quadratic formula. Find real and complex roots, discriminant, vertex, and axis of symmetry.
The quadratic formula solves ax²+bx+c=0: x = (-b ± √(b²-4ac)) / 2a. The discriminant (b²-4ac) determines root types: positive = 2 real roots, zero = 1 root, negative = complex roots.