Let's analyze each function to determine if it is linear or not.

Function 1

Function 1 is given as a set of points: $(0, -5), (4, -4), (8, -3), (12, -2)$.

To determine if it is linear, we need to check if the rate of change (slope) between each consecutive point is constant:

• Between $(0, -5)$ and $(4, -4)$: $\frac{-4 - (-5)}{4 - 0} = \frac{1}{4}$
• Between $(4, -4)$ and $(8, -3)$: $\frac{-3 - (-4)}{8 - 4} = \frac{1}{4}$
• Between $(8, -3)$ and $(12, -2)$: $\frac{-2 - (-3)}{12 - 8} = \frac{1}{4}$

Since the slope is constant, Function 1 is linear.

Function 2

Function 2 is given as a set of points: $(3, 4), (6, 7), (9, 11), (12, 17)$.

Check if the slope is consistent:

• Between $(3, 4)$ and $(6, 7)$: $\frac{7 - 4}{6 - 3} = 1$
• Between $(6, 7)$ and $(9, 11)$: $\frac{11 - 7}{9 - 6} = \frac{4}{3}$

The slope is not constant (changes from 1 to $\frac{4}{3}$), so Function 2 is not linear.

Function 3

Function 3 is presented in a table format, showing that all $y$ values are $-3$, regardless of $x$: