function table and rules?!?

[Zenyatta]

I've never been good at these,but usually I can pull something together....this one is stumping me though!

x y
0.5 2
1 1
2 0.5
4 0.25
5
10

I completed the table by putting: 5 .125
10 .0625

But I cant seem to find a function that shows the relationship between x and y!?

 

[Deleted member 4993]

I've never been good at these,but usually I can pull something together....this one is stumping me though!

x y
0.5 2
1 1
2 0.5
4 0.25
5
10

I completed the table by putting: 5 .125
10 .0625

But I cant seem to find a function that shows the relationship between x and y!?

Rewrite the x's and y's as fractions - it will be very clear.