Max@Math Revolution wrote:[GMAT math practice question]
In the x-y plane, does the parabola y=ax^2+bx+c have x-intercepts?
1) b^2-4ac<0
2) a<0
For any parabola of the form y = ax² + bx + c, the DISCRIMINANT is equal to b² - 4ac.
If the discriminant is positive, then the parabola has two x-intercepts.
If the discriminant is equal to 0, then the parabola has one x-intercept.
If the discriminant is negative, then the parabola has no x-intercepts.
Statement 1:
Since the discriminant is negative, the parabola has no x-intercepts.
Thus, the answer to the question stem is NO.
SUFFICIENT.
Statement 2:
No way to determine whether the discriminant is positive, negative, or equal to 0.
INSUFFICIENT.
The correct answer is
A.
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