A way to 'differentiate' or find 'delta' between surfaces

Hi everyone,

I'm neither a matlab expert nor a mathematician.

I have more than 2 complex surface plots based on equations that resemble z = x + 2y.

Imagine I have three equations like so:

z = x + 2y; z = 2x + 2y; z = 3x + 2y;

Is there a way to find out [x,y,z] values or range of values where each formula deviates from others?

I am trying to find out values or range of values which are unique to each formula and not 'had' by other formulas?

Does this make sense? I can clarify further if needed.

Thank you

[dpb]

Not sure I follow exactly, but if you write the set of equations as

z=a.*x + b.*y;

then

a=[1 2 3]; 
b=[2 2 2];

you can use unique and friends for examining the coefficients.