Clearly, the lowest number is 0, and the highest is 9. So B is the right answer.
Notice that if you had plugged in only –2 and 2, you would have incorrectly
gotten D as the answer instead.
GRAPHING FUNCTIONS
Still with us? Good, because now we get to use those charts. The best thing
about functions is that we can graph them and see them on the page.
Let’s make a table for a new function:
f (x) = 2x + 5
x y
–3 –1–2 1–1 3
0 5
1 7
2 9
3 11
A collection of (x,y) coordinate pairs is called a relation, and if we plot each
pair on the standard xy-plane, and draw a line to connect the dots, then we’ll get
something like this: