Symbols:E

Identity Element
$$e$$

Used to indicate the identity element in a general algebraic structure.

If $$e$$ is the identity of the structure $$\left({S, \circ}\right)$$, then a subscript is often used: $$e_S$$.

This is particularly common when more than one structure is under discussion.

The LaTeX code for $$e_S$$ is e_S.

Euler's number
$$e$$

$$e$$ is the base of the natural logarithm, $$\operatorname{ln}$$. It is defined to be the unique real number such that the value of the function $$e^x$$ has the same value as the slope of the tangent line to the graph of the function.

The LaTeX code for $$e$$ is e.