Which relation is a function?

A.
{(5, 5), (5, 9), (5, 15)}

B.

{(–5, 1), (4, 9), (6, 10)}

C.

{–2, 10), (–6, 10), (–2, 3)}

D.

{(0, 3), (0, 9), (12, –4)}

Question

Which relation is a function?  
 
 

 
 

  

  A. 
  {(5, 5), (5, 9), (5, 15)}   
   

 
 

  

  B. 
 
{(–5, 1), (4, 9), (6, 10)}
  
   

 
 

  

  C. 
 
{–2, 10), (–6, 10), (–2, 3)}
  
   

 
 

  

  D. 
 
{(0, 3), (0, 9), (12, –4)}

anonymous · Answer

B is a function. Any function that has two points with the same 2 x values isn't a function. You could test using the straight line test. This means that if you put a straight line down the function, and it passes through two points, it's not a function. If it passes through one no matter where you put it, it is a function.

anonymous · Answer

the answer is b @PrinceMMQ