1. which of the following represents a function?
x -2 -1 0 -1 -2
y 2 3 4 5 6

x 1 1 0 2 2
y 1 2 3 4 5

x 1 2 3 4 5
y 2 2 3 3 4

x 1 1 1 1 1
y 2 3 4 5 6

2. what is the domain of the function: {(2, 1); (4, 2); (6, 3); (8, 4)}?
{1, 2, 3, 4}
{1, 2, 3, 4, 6, 8}
{2, 4, 6, 8}
{6, 8}

3. what is the range of the function: {(2, 1); (4, 2); (6, 3); (8, 4)}?
{1, 2, 3, 4}
{1, 2, 3, 4, 6, 8}
{2, 4, 6, 8}
{6, 8}

4. suppose p varies directly with d, and p = 7 when d = 3. what is the value of d when p = 28?
4/3
12
16
140/3

5. given the function t(z) = 7 − z, find t(−4).
−11
11
−3
3
6. what is the equation of the graph?

f(x) = − |x| + 2
f(x) = − |x| − 2
f(x) = − |x + 2|
f(x) = − |x − 2|
7. the number of calories burned, c, varies directly with the time spent exercising, t. when dennis walks for 4 hours, he burns 800 calories. which of the following equations shows this direct linear variation?
c = t
c = 800t
c = 4t
c = 200t