Willis analyzed the following table to determine if the function it represents is linear or non-linear. first he found the differences in the y-values as 7 – 1 = 6, 17 – 7 = 10, and 31 – 17 = 14. then he concluded that since the differences of 6, 10, and 14 are increasing by 4 each time, the function has a constant rate of change and is linear. what was willis’s mistake?

x
y
1
1
2
7
3
17
4
31
he found the differences in the y-values as 7 – 1 = 6, 17 – 7 = 10, and 31 – 17 = 14.

he determined that the differences of 6, 10, and 14 are increasing by 4 each time.

he concluded that the function has a constant rate of change.

he reasoned that a function that has a constant rate of change is linear.