I am looking at a pattern in some data, and I am trying to figure out if it tells me anything about the underlying structure of the dataset, or if this is just an obvious algebraic relationship I am missing.
The explicit relationship between variables is A + B = C.
![Data plotted][1]
The first thing to note is that the data is periodic.
Then, disregarding the relation $A+B=C$, the blue line is similar to the black line, so you could state, by algebra, that the blue line is a multiple of the black line (i.e. multiplication by some factor). The orange line can be described by both the orange and blue line, as it is the 'opposite' of those lines, multiplied by some factor (or, mathematically, multiplied by the -1 and then by some factor).
If you want to practise these kind of algebraic results, use the periodic function $\sin(x)$. Then, multiply it by a factor, e.g. 2, to get the same pattern, but with a different amplitude. Then, take the negative of $\sin(x)$ and multiple by some factor, e.g. 4, to get the opposite. Plotting my previous analogy:
Otherwise, you could make a substitution in $(C_1 - C_0)/\Delta C_0$ since $A+B=C$. This tells us that \begin{equation} (C_1 - C_0)/\Delta C_0 = \dfrac{(A+B)_1 - (A+B)_0}{\Delta(A+B)_0} = \dfrac{A_1+B_1 - A_0 -B_0}{\Delta(A_0 + B_0)} \end{equation} which explains the visual relationship maybe somewhat more. Nevertheless, it depends on the interpretation of $A,B,C$ themselves to come up with a useful result.