ANSWER
B. 1
EXPLANATION
The given function is

This is a piece-wise defined function.
We want to find f(1)
We substitute x=1 into f(x)=x because, 1 belongs to the interval,
1≤x≤5
f(1)=1
The correct answer is B.
V = pi x R^2 x height
V= pi x 6^2 x 12
V= 432 pi (m^3)
To solve this problem you must apply the proccedure shown below:
1. You have the following parent function given in the problem above: 
2. If you want to shift this parent function up six units, you only have the add a
, then, you will obtain the following new function:

Therefore, as you can see, the answer is: 
The area of the rectangle is 48 m
The answer is d, because you can make it into percent and make it into graphs