1. ## Understanding Function Notation?

I have a question in my textbook that I can not figure out. I am still a little bit confused about all of this because I haven't done any of it in a while.
The question is:

Evaluate f(4) for each of the following:
a) f= {(1,5), (3,2), (4,1), (6,2)}
b) is a chart with x and f(x) values
c) is the equation f(x) 3x^2 - 2x + 1
d) is a graph

The only one I know how to evaluate is the equation. I am not sure what to do with the set of ordered pairs. once I can understand what needs to be done there, I am sure I'll understand how to do the other two. I am thinking that I need to take an ordered pair and make it into an equation but I am not sure? Hopefully someone can explain what this is asking? Thanks.

2. Alright, I did a few more questions and came back to this one and found the answer. I thought I'd post it incase anyone ever runs into this problem.
y= f(x)
a) y= f(x)
y= f(4)
y= 1 ...... I just found the function where X=4 and the answer for y is 1
b) I just took the value for x from the chart and found the value that went with it for f(x)... since f(x) = y
c) I found the point where f(4) was and noted what the y value was

I guess it was a pretty simple question that I made complicated in my head before I did it. It really helps to skip ahead to the next question sometimes...