I'm guessing this is a question about interest rates? If you have $20 that increases by 4% in one year, you need to multiply 20 by 1.04. This gets you $20.8. 
If you are talking about compound interest, we will take this number and multiply it again by 1.04 for the second year. 20.8 x 1.04 = $21.632. 
If it is instead simple interest, we will simply add another .8 dollars for each year, instead of getting 4% interest compounded every year onto the new value. This gets you $21.6.
        
             
        
        
        
Answer with Step-by-step explanation:
We are given that 

For each real number 
To prove that f is one -to-one.
Proof:Let  and
 and  be any nonzero real numbers such that
 be any nonzero real numbers such that 

By using the definition of f to rewrite the left hand side of this equation 

Then, by using the definition of f to rewrite the right hand side of this equation  of 

Equating the expression then we get 




Therefore, f is one-to-one.
 
        
             
        
        
        
Answer:
Vertical Asymptotes:  
x=-1,0
Horizontal Asymptotes:  
y=0
No Oblique Asymptotes