\delta
The Greek letter delta (\delta) is commonly used in mathematics and science to represent a change or difference in a variable. It is often used in calculus, physics, and engineering to denote small changes or variations in quantities.
Represents a small change or difference in the variable x.
\delta x
Used in calculus to denote the change in y corresponding to a small change in x.
\delta y = f(x+\delta x) - f(x)
Represents a small change in volume in three-dimensional space.
\delta V = \delta x \cdot \delta y \cdot \delta z