Parabola Property: Analyzing Positive Values with X-Axis Vertex

Question

If the vertex of a parabola is on the x-axis and the parabola is bending upwards, then the function is always positive except for the vertex point.

Step-by-Step Solution

To solve this problem, follow these steps:

  • Step 1: Recognize that the standard form of a quadratic function is f(x)=a(xh)2+k f(x) = a(x - h)^2 + k , which represents a parabola.
  • Step 2: Since the parabola is upward-opening, the coefficient a a is positive, a>0 a > 0 .
  • Step 3: Given that the vertex is on the x-axis, the vertex has coordinates (h,0) (h, 0) , which means k=0 k = 0 .
  • Step 4: Substitute k=0 k = 0 into the standard form to get f(x)=a(xh)2 f(x) = a(x - h)^2 .
  • Step 5: Since a>0 a > 0 , the expression a(xh)2 a(x - h)^2 is always non-negative because (xh)20 (x - h)^2 \geq 0 for all x x .
  • Step 6: At the vertex x=h x = h , f(h)=a(hh)2=0 f(h) = a(h - h)^2 = 0 ; at any other point, f(x)>0 f(x) > 0 since a(xh)2>0 a(x - h)^2 > 0 .

Therefore, the function value is zero at the vertex and positive everywhere else. This confirms that the statement is correct.

The correct answer to the problem is Correct.

Answer

Correct