Question

5.
For which discriminant is the graph possible?

A. b2 – 4ac = –1
B. b2 – 4ac = 0
C. b2 – 4ac = 4

Answer 1

C is the only one that will give two real roots (cross the x axis twice)

A has no real roots - the square root of -1 is not real
B has two identical roots - the parabola touches the x axis at one point