Which statement best explains whether the data in the following table represents a linear or nonlinear function?

x y
−4 4
−1 2.5
0 2
4 0
The table represents a nonlinear function because the graph shows a rate of change that is decreasing.
The table represents a linear function because the graph shows a rate of change that is increasing.
The table represents a nonlinear function because the graph does not show a constant rate of change.
The table represents a linear function because the graph shows a constant rate of change.

1 answer

To determine if the data in the table represents a linear or nonlinear function, we need to check if there is a constant rate of change (slope) between the pairs of (x, y) values.

Let's calculate the changes in y divided by the changes in x:

  • From \(x = -4\) to \(x = -1\): \[ \Delta y = 2.5 - 4 = -1.5 \quad \Delta x = -1 - (-4) = 3 \quad \text{slope} = \frac{-1.5}{3} = -0.5 \]

  • From \(x = -1\) to \(x = 0\): \[ \Delta y = 2 - 2.5 = -0.5 \quad \Delta x = 0 - (-1) = 1 \quad \text{slope} = \frac{-0.5}{1} = -0.5 \]

  • From \(x = 0\) to \(x = 4\): \[ \Delta y = 0 - 2 = -2 \quad \Delta x = 4 - 0 = 4 \quad \text{slope} = \frac{-2}{4} = -0.5 \]

In this case:

  • From \(x = -4\) to \(x = -1\), the slope is \(-0.5\).
  • From \(x = -1\) to \(x = 0\), the slope is \(-0.5\).
  • From \(x = 0\) to \(x = 4\), the slope is also \(-0.5\).

Since the slope (rate of change) is constant for all intervals, the data represents a linear function.

Based on this assessment, the correct statement is:

The table represents a linear function because the graph shows a constant rate of change.