Assertion: parabola's vertex | /r/HasProperty | below the x x x-axis
Facets:
Source sentences:
text: If the vertex is below the x x x-axis (or on the x x x-axis), we will obtain two real roots.
text: a > 0 a>0, we can say that the vertex must be below the x x x-axis and the equation will have real roots, without computing the discriminant.