Use the image to answer the question.

Question

A parabola is graphed on a coordinate plane. The x-axis ranges from negative 10 to 3 in increments of 1. The y-axis ranges from negative 10 to 10 in increments of 1.

Determine whether the a-value is positive or negative. Provide an appropriate reason.

(1 point)
Responses

The a-value is positive because the graph is of a parabola that opens up.
The a -value is positive because the graph is of a parabola that opens up.

The a-value is negative because the graph is of a parabola that opens down.
The a -value is negative because the graph is of a parabola that opens down.

The a-value is negative because the y-intercept is negative.
The a -value is negative because the y -intercept is negative.

The a-value is negative because the x-intercepts are negative.
The a -value is negative because the x -intercepts are negative.

Answer 1

To determine the sign of the a-value in a parabola, we look at the direction the parabola opens:

• If the parabola opens upward, the a-value is positive.
• If the parabola opens downward, the a-value is negative.

Since the question states that you are observing a parabola, you'll need to identify whether it opens upward or downward based on its shape.

Assuming you observed that the parabola opens downward (which commonly happens if the vertex is at the highest point and the arms are pointing down), then:

The correct response would be: "The a-value is negative because the graph is of a parabola that opens down."

This means that the correct answer from the provided options would be: "The a -value is negative because the graph is of a parabola that opens down."