Question

Which table represents a quadratic function?

Answer 1

9514 1404 393

Answer:

  see below

Step-by-step explanation:

The x-values in each table are evenly-spaced (increasing by 2). So, the quadratic function can be identified by its second differences: they will be a non-zero constant.

Table 1 has first differences that are constant at 3. -2-(-5) = 3, for example. It represents a linear function.

Table 2 has first differences of 4, 8, 4, 4, neither constant, nor linearly increasing. The function does not have a name.

Table 3 has first differences of -9, -3, +3, +9, and these have differences of +6. This represents a quadratic function.

Table 4 has first differences of 0.5, 1, 2, 4. These have a constant ratio, as do the values in the table. It represents an exponential function.