Question

Okay, I have a question regarding the criteria a x|y table needs to have in order to be considered a function.

Answer 1

first column cannot have repeating numbers
that is the entire idea

Answer 2

I know for every x coordinate there can only be one y coordinate but does there have to be a pattern? Like in this table.

X|y
-3|-8
-2|-5
1|0
0|7
3|9
4|15

It doesn't seem to have a pattern. Does that make it not a function?

Answer 3

do the first number repeat?

Answer 4

No

Answer 5

then it is a function

Answer 6

So it doesn't matter if I cant see a pattern.

Answer 7

that relates the numbers together.

Answer 8

in the olden days, over 300 years ago, mathematicians believed that a function had to be given by an equation (or a pattern as you suggest) but that proved too limiting to the concept
these days all that is necessary is that no one input gives two different outputs, meaning that no first number can repeat

Answer 9

Awesome. :) thanks.

Answer 10

so you can basically pick numbers completely at random
thing of the stock market,
if you knew what the dow would be each day (input: day, output: dow average)
you would be a billionaire and wouldn't have to do math homework

Answer 11

yw

Answer 12

:) I wish

Answer 13

yeah, me too