Answer:
a. Negative discriminant: above
b. Positive discriminant: below
c. Discriminant is zero: on
Explanation:
If the discriminant is negative, then there are no real zeros. We have an upward-facing parabola, then the vertex is located above the x-axis
If the discriminant is positive, then there are two different real zeros. We have an upward-facing parabola, then the vertex is located below the x-axis
If the discriminant is zero, then there is one zero. We have an upward-facing parabola, then the vertex is located on the x-axis