Question 174633
I have already answered question 3 but here it is again:

Look at a point more closely. 
Here is the general point: (x,y) 
x = domain 
y = range 
If any of the x points repeat, then there is no function. 
Here is your function: 
{(-2,-1),(-1,-4),(0,-5),(1,-4),(3,4)} 
Look at the x points and they are: 
-2, -1, 0, 1 and 3 
Do any of the integers repeat? 
No, right? 
So, this is a funtion. 
The answer is (b). 
NOTE: Notice that the range has two -4. You only need to list one of them for the range when numbers repeat. It does not matter if the y values repeat.
The x values cannot repeat because it would take x to two different destinations. 
Understand?