The Dirac delta function $\delta(t)$ is defined as
- $\delta(t)= \begin{cases}1, & t=0 \\ 0, & \text { otherwise }\end{cases}$
- $\delta(t)= \begin{cases}\infty, & t=0 \\ 0, & \text { otherwise }\end{cases}$
- $\delta(t)=\left\{\begin{array}{ll}1, & t=0 \\ 0, & \text { otherwise }\end{array}\right.$ and $\displaystyle{} \int_{-\infty}^\infty \delta(t) d t=1$
- $\delta(t)=\left\{\begin{array}{ll}\infty, & t=0 \\ 0, & \text { otherwise }\end{array}\right.$ and $\displaystyle{}\int_{-\infty}^\infty \delta(t) d t=1$