Answer:
c. r^2 -4qs
Step-by-step explanation:
When compared to the standard quadratic ...
ax^2 +bx +c = 0
we find that your quadratic has ...
a = q, b = r, c = s
Substituting these into the formula for the discriminant, we get ...
d = b^2 -4ac = r^2 -4qs
The discriminant is r^2 -4qs.