Parabola Property Analysis: Vertex Position Below X-axis and Positive Values

Question

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

Step-by-Step Solution

To analyze this problem, we'll follow these steps:

  • Step 1: Understand the structure of a quadratic function.
  • Step 2: Explore the implications of the vertex location below the x-axis.
  • Step 3: Analyze specific conditions where the function might not be always positive.

Step 1:
A parabola y=ax2+bx+c y = ax^2 + bx + c opens upwards if a>0 a > 0 .

Step 2:
The vertex form of a quadratic is y=a(xh)2+k y = a(x-h)^2 + k , where (h,k) (h, k) is the vertex. If k<0 k < 0 , the vertex is below the x-axis, making y y negative at x=h x = h (the minimum point for an upward-opening parabola).

Step 3:
Since y y at the vertex is k<0 k < 0 , it implies the function is negative at least at this point. Thus, the function cannot always be positive, as there exists at least one point where it is non-positive (negative).

Therefore, the assertion that the parabola is always positive is incorrect.

The correct answer is: Incorrect.

Answer

Incorrect