Question

Which kind of function best models the data in the table? Graph the data and write an equation to model the data.

linear; y = x – 1


linear; y = –x – 1


quadratic; y = x2 – 1


exponential; y = 3x – 1

Answer 1

Linear; y=-x - 1

The slope is negative since it’s decreasing. So it’s not the first equation. It’s not a quadratic equation because there is no forming U shape for this data. It’s not a exponential function because the slope is not 3 and a exponential function is in the form y=a(b)^x

Answer 2

The correct answer is B) linear; y = –x – 1

Explanation:

To find this, use any values in the table and it will produce a true statement. This is how we check to see if a model is correct. See the two examples below for proof.

(4, 5)

y = -x - 1

-5 = -4 - 1

- 5 = -5 (TRUE)

(0, -1)

y = -x - 1

-1 = 0 - 1

-1 = -1 (TRUE)