Answer:
Not a function.
Step-by-step explanation:
There must only be one output per input but here we see the input 18 has two outputs ; 3 and 15 therefore this is not a function. 
 
        
             
        
        
        
The polynomial function is shown about between 10 and 15.
        
                    
             
        
        
        
Answer:
2 pi 
Step-by-step explanation:
The radius is 2
The area of a circle is 
A = pi r^2
We have 1/2 of a circle so
1/2 A = 1/2 pi r^2
          =1/2 pi ( 2)^2
          =1/2 pi *4
       = 2 pi 
 
        
             
        
        
        
The length of the base 3 times the width. And we need to express the surface. I'm assuming the surface of the base. So, to get the area of the base, multiply w * l.