Parabola Property: Analyzing Negative Values for X-Axis Vertex Functions

Question

If the vertex of a parabola is on the x-axis and the parabola is bending downwards, then the function is always negative except at the vertex point.

Step-by-Step Solution

To solve this problem, let's analyze the given conditions:

  • Step 1: We examine the standard form of a downward-opening parabola. The standard vertex form is y=a(xh)2+k y = a(x - h)^2 + k . If the vertex lies on the x-axis, k=0 k = 0 , so the equation simplifies to y=a(xh)2 y = a(x - h)^2 .
  • Step 2: Since the parabola is bending downwards, it implies that a<0 a < 0 . Therefore, the quadratic term a(xh)2 a(x - h)^2 is non-positive for all values of x x , becoming 0 only when x=h x = h .
  • Step 3: Evaluate the function for xh x \neq h . For any xh x \neq h , (xh)2>0 (x - h)^2 > 0 , so y=a(xh)2<0 y = a(x - h)^2 < 0 because a<0 a < 0 .

Conclusively, the function value is always negative for all xh x \neq h , and it is exactly zero at x=h x = h (the vertex). The statement provided corresponds precisely with this behavior.

Therefore, the statement that the function is always negative except at the vertex point is indeed Correct.

Answer

Correct