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

(0.25,8.375) is the high point on the parabola.
left parenthesis 0.25 comma 8.375 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.

(0.5,9) is the high point on the parabola.
left parenthesis 0.5 comma 9 right parenthesis is the high point on the parabola.

(−1,−1) is the low point on the parabola.

1 answer

To determine the vertex (high or low point) of the parabola described by the quadratic equation \( y = -6x^2 + 3x + 8 \), we first need to find the vertex of the parabola. The formula for the x-coordinate of the vertex of a quadratic function \( y = ax^2 + bx + c \) is given by:

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

In this case, \( a = -6 \) and \( b = 3 \):

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

Next, we find the y-coordinate of the vertex by substituting \( x = 0.25 \) back into the equation:

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

Thus, the vertex of the parabola is \( (0.25, 8.375) \).

Since the coefficient of \( x^2 \) (which is \( -6 \)) is negative, this indicates that the parabola opens downwards. Therefore, the vertex represents the high point of the parabola.

Given these calculations, the correct response is:

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