Functions

Green’s functions Green’s functions are used primarily as a method of solving linear differential equations. A green’s function will be denoted as G(t, t’), where it is technically a function of two variables, t and t’.

Dirac-Delta Function These things are the most annoying as fuck functions you will see actually exist in mathematics. Basically, a dirac-delta function, labelled δ(x), is defined as follows: $$ \tag{☆}\delta(x)= \begin{cases} 0 & \quad x \neq 0 \newline \infty & \quad x = 0 \end{cases} $$