The first one and the third one are correct. because for the when you plug 1 on the first piece wise function you get 3. 
f(3) =1. and f(1)=3 so f(1)>f(3)
        
                    
             
        
        
        
Answer:
How tall is he semicirlce?
Step-by-step explanation:
Then I can solve
 
        
             
        
        
        
Growth rate = 200% each year
SO population becomes twice in each year
After 20 years, population = 5* 2^20 = 5242880
(Assuming no deaths occur) 
        
                    
             
        
        
        
The corcumference C of a circle is C= 2 x pie x radius
So radius= C/(2pie)
Volume of cylinder= pie x r(squared) x h