Question

(BEST ANSWER GETS MEDAL!) Is {(1,1),(2,3),(3,4)} a function? If yes, evaluate for f(2).

Answer 1

When you have a set of ordered pairs like that, the fastest way to tell if it's a function is to look at the x-values. If all of the x-values are different (no repeats), then YES it is a function.

If you do have a function, f(2) means evaluate the function when x=2, meaning what is y when x is 2? So you can look at the point where the x-coordinate is 2, then your answer is the y-coordinate of that point.

Answer 2

Ooh Ok so this would be a function?

Answer 3

Yep! Can you figure out f(2)?

Answer 4

I'm not really sure how to do that... Could you walk me through it?

Answer 5

Typically f(x) is how we label a function. So if they want f(2), that just means x=2. See how they replaced the x in f(x) with a 2 in f(2)?

So they want to know the y-value when x=2. Look at your list of points and see which point has a 2 in the x-position (the first number of the ordered pair). The answer to f(2) is the y-value of that point (the second number of the ordered pair).

Answer 6

Ooh thank you so much!

Answer 7

You're welcome!