Answer:
see below
Step-by-step explanation:
The functions for these tables are, respectively, ...
f(x) = 5 - x
f(x) = 3x
f(x) = (x -1)² . . . . . a quadratic relation
f(x) = 4x² . . . . . . a quadratic relation
We assume the intention is that the terminology "quadratic variation" mean "proportional to the square of x". In that case, only the last function has such variation.
