Answer:
18
Step-by-step explanation:
Since f '(x) ≥ 3, that means for every x, it can increase by 3 or greater. If we want to find the smallest f(5), we have to use the smallest rate of change possible, which is just 3.
Then, we have to find how many times x changes. Since we are going from 3 to 5, that means x changes 2 times. (5 - 3 = 2)
Now we multiply the rate of change (3) by the number of x changes.
3 x 2 = 6
We then add that to 12 since that is the number we started with
12 + 6 = 18
