Difference of curves?

[LordBrown]

If I have two polynomial equations that are correlated but I don't know the relationship, can I simply subtract the equations to get a function to change a result from one curve into the correlated result on the other curve?

 

[Dr.Peterson]

If I have two polynomial equations that are correlated but I don't know the relationship, can I simply subtract the equations to get a function to change a result from one curve into the correlated result on the other curve?

What sort of "correlation" are you imagining? What reason do you have for thinking they are correlated?