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

(0.5,9)
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.

(−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.

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

1 answer

To find the values for the high or low point of the parabola represented by the quadratic equation \( y = -6x^2 + 3x + 8 \), we can start by completing the table for the specified x-values.

Let's calculate \( y \) for the missing \( x \) values in the table:

  1. For \( x = -1 \): \[ y = -6(-1)^2 + 3(-1) + 8 = -6(1) - 3 + 8 = -6 - 3 + 8 = -1 \] So, the entry is \((-1, -1)\).

  2. For \( x = -0.25 \): \[ y = -6(-0.25)^2 + 3(-0.25) + 8 = -6(0.0625) - 0.75 + 8 = -0.375 - 0.75 + 8 = 6.875 \] So, the entry is \((-0.25, 6.875)\).

  3. For \( x = 0.5 \): \[ y = -6(0.5)^2 + 3(0.5) + 8 = -6(0.25) + 1.5 + 8 = -1.5 + 1.5 + 8 = 8 \] So, the entry is \((0.5, 8)\).

  4. For \( x = 0.75 \): \[ y = -6(0.75)^2 + 3(0.75) + 8 = -6(0.5625) + 2.25 + 8 = -3.375 + 2.25 + 8 = 6.875 \] So, the entry is \((0.75, 6.875)\).

The completed table is as follows:

| \( x \) | \( y \) | |-----------|-------------| | -1 | -1 | | -0.75 | 2.375 | | -0.5 | 5 | | -0.25 | 6.875 | | 0 | 8 | | 0.25 | 8.375 | | 0.5 | 8 | | 0.75 | 6.875 | | 1 | 5 |

Finding the High or Low Point

Since the coefficient of \( x^2 \) in the equation \( y = -6x^2 + 3x + 8 \) is negative (-6), this indicates that the parabola opens downwards, and thus, it will have a high point (the vertex).

The vertex of a parabola given by \( ax^2 + bx + c \) is found at: \[ x = -\frac{b}{2a} \]

Here, \( a = -6 \) and \( b = 3 \):

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

Let’s calculate \( y \) at this \( x \):

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

Thus, the vertex (high point) is at \( (0.25, 8.375) \).

Conclusion

  • The point \( (0.25, 8.375) \) is the high point.
  • Therefore, the correct response from the options given is:

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