Parabola Properties: Analyzing Negative Values with Downward-Facing Vertex Below X-axis

Question

If a parabola is bending downwards and its vertex is below the x-axis, then it is always negative.

Step-by-Step Solution

The problem concerns a downward-opening parabola with a vertex below the x-axis. Let's elaborate on these terms to determine if the given statement is correct:

  • Step 1: Identify Quadratic Form
    We consider a quadratic function f(x)=ax2+bx+c f(x) = ax^2 + bx + c with a<0 a < 0 since it opens downwards.
  • Step 2: Understand the Vertex's Position
    The vertex form of the quadratic is f(x)=a(xh)2+k f(x) = a(x - h)^2 + k . Given that the vertex is below the x-axis, the condition k<0 k < 0 holds. The vertex at coordinate (h,k)(h, k) is the maximum point of the parabola.
  • Step 3: Evaluate the Parabola's Sign
    Since k<0 k < 0 , the vertex (h,k) (h, k) is the highest point of the parabola lying below the x-axis. Consequently, all other points on the parabola satisfy f(x)k<0 f(x) \leq k < 0 .

Therefore, the entire quadratic function is negative for all values of x x due to the vertex being the maximum and its y-coordinate being negative. Thus, the statement that such a parabola is always negative is indeed "correct".

Thus, the correct choice is: Correct \text{Correct} .

Answer

Correct