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 y-intercept is negative.
The a -value is negative because the y -intercept is negative.
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 x-intercepts are negative.
1 answer
The correct response is:
The a-value is negative because the graph is of a parabola that opens down.
A parabola opens downwards when the a-value (the coefficient of the x² term in the quadratic equation) is negative. This is visually confirmed by the shape of the parabola on the graph.
