Evaluate or estimate each expression based on the following
table.
𝑥 −3 −2 −1 0
𝑓(𝑥) 1 2 4 2
1 2
3
1 0.5 0.25
a) 𝑓 (0)
b) 𝑓 (2)
c) 𝑓 (1) − 𝑓(−1)
d) 𝑓 (1)𝑓(−2)
Solutions:
For each part, remember that the quantity in the parentheses
after the 𝑓 is an 𝑥-value (an input value), and you want to find
the corresponding output value. To do this, just look along the
first row of the table until you find the input value you’re
looking for, and then see what output value goes with it (the
number that’s directly below it is the output value).
For parts a) and b), 𝑓(0) = 2 and 𝑓 (2) = 0.5.
For part c), 𝑓(1) = 1 and 𝑓 (−1) = 4, so
𝑓 (1) − 𝑓 (−1) = 1 − 4 = −3
For part d), 𝑓(1) = 1 and 𝑓 (−2) = 2, so
𝑓(1)𝑓(−2) = (2)(1) = 2