y = 1x² − 4

Vertex (0, −4)

Roots x = −2, 2

Discriminant 16 → 2 real roots

Reading the plot. The orange dot is the vertex (the parabola's turning point). White dots on the x-axis are the real roots — where the curve crosses zero. The discriminant tells you whether a quadratic has two real roots, one repeated root, or none. URL updates as you drag, so any state you find is shareable. Why I build tools like this →