TITLE: Is there an analogue to the "Delta" symbol for ratios?
QUESTION [20 upvotes]: A capital delta ($\Delta$) is commonly used to indicate a difference (especially an incremental difference). For example, $\Delta x = x_1 - x_0$
My question is: is there an analogue of this notation for ratios?
In other words, what's the best symbol to use for $[?]$ in $[?]x = \dfrac{x_1}{x_0}$?

REPLY [3 votes]: The greek letter $\Delta$ stands for Difference
So the symbol for the multiplicative increase of variable should be related to letter $Q$ in greek which is the ancient Qoppa letter and stands for Quotient