Answer:
Part a) 

Part b) 
 (see the explanation)
Explanation:
we know that
The volume of a cylinder is equal to

where
B is the area of the base of cylinder
h is the height of the cylinder
we have that

Part a) Write the function, V(h), that represents the volume of the cylinder
we have 
 ----> the radius is half the diameter
substitute


The volume is 

Part b) Find V(3) and tell what it represents
V(3) represent the volume of the cylinder with a height of 3 inches
so
For h=3 in
substitute

