x f(x)
2.0 2.8
2.5 1.1
3.0 0.8
3.5 1.2
4.0 0.3
4.5 0.7
A. between 2.0 and 2.5 and between 4.0 and 4.5
B. between 2.5 and 3.0 and between 4.0 and 4.5
C. between 2.0 and 2.5 and between 3.5 and 4.0
D. between 2.5 and 3.0 and between 3.5 and 4.0
1 Answer

Look at the signs for f(x). The interval where the signs change is where the zeros are, i.e. where they cross the yaxis.
So the answer is B.
Hint: Try plotting out the table on a graph, x is the values of x and f(x) the values of y. When you connect the dots you'll see how the answer makes sense.