Answer:
"[tex]b^2-4ac=4[/tex]"
Step-by-step explanation:
By looking at the value of the discriminant in a quadratic, we can find the nature of roots.
Let the value of the discriminant be "D", so we can say:
- D > 0 [2 distinct real roots]
- D = 0 [2 same real roots]
- D < 0 [no real roots]
Graphically, we can write the points in order as:
- D > 0, 2 cutting point in x-axis
- D = 0, 1 touching point in x-axis
- D < 0, NO cutting/touching point in x-axis
Looking at the graph, we clearly see that there is 2 cutting points in the x-axis, so there are 2 roots. This means the value of the discriminant should be greater than 0 (positive value).
Out of the 3 choices given with discriminant formula, the last one has a value that is greater than 0:
4 > 0
Hence, last answer choice is right.
