Doesn't fit for all

Question

I can see that 2^x can work in (1,2) and (2,4), but it doesn't fit for the remaining 3. I need one that works for all 5 relations.

Answer 1

It works for all values of x. For example, f(5)=2^5=2*2*2*2*2=32 where the ordered pairs are (x,f(x)) when f(x)=2^x, for 1<x<5, at least.