Given the table of values, complete the table for the quadratic equation y=−6x2+3x+8 to find the values of the high or low point of the parabola. x y −1 −1 −0.75 2.375 −0.5 5 −0.25 0 8 0.25 8.375 0.5 0.75 1 5 Which of the following is correct? (1 point) Responses (−1,−1) is the low point on the parabola. left parenthesis negative 1 comma negative 1 right parenthesis is the low point on the parabola. (0.5,9) is the high point on the parabola. left parenthesis 0.5 comma 9 right parenthesis is the high point on the parabola. (0.25,8.375) is the low point on the parabola. left parenthesis 0.25 comma 8.375 right parenthesis is the low point on the parabola. (0.25,8.375) is the high point on the parabola.

1 answer

To determine the high or low point (vertex) of the quadratic equation \( y = -6x^2 + 3x + 8 \), we first need to confirm that this equation represents a parabola that opens downward (since the coefficient of \( x^2 \) is negative).

The vertex of a parabola given in the form \( y = ax^2 + bx + c \) can be found using the formula:

\[ x = -\frac{b}{2a} \]

For the quadratic equation \( y = -6x^2 + 3x + 8 \):

  • \( a = -6 \)
  • \( b = 3 \)

Plugging in these values:

\[ x = -\frac{3}{2(-6)} = -\frac{3}{-12} = \frac{1}{4} = 0.25 \]

Now we substitute \( x = 0.25 \) back into the equation to find the corresponding \( y \) value:

\[ y = -6(0.25)^2 + 3(0.25) + 8 \] \[ y = -6(0.0625) + 0.75 + 8 \] \[ y = -0.375 + 0.75 + 8 \] \[ y = 0.375 + 8 \] \[ y = 8.375 \]

So the vertex (or the high point of the parabola) is at \( (0.25, 8.375) \).

Now let's review the provided options:

  1. \((-1, -1)\) is the low point on the parabola.
  2. \((0.5, 9)\) is the high point on the parabola.
  3. \((0.25, 8.375)\) is the low point on the parabola.
  4. \((0.25, 8.375)\) is the high point on the parabola.

Since we found that the vertex is at \( (0.25, 8.375) \) and the parabola opens downward, this means that \( (0.25, 8.375) \) is the high point, not the low point.

Therefore, the correct response is:

\((0.25, 8.375)\) is the high point on the parabola.