EQUAÇÕES GRACELI [40]

[ ${\frac {\pi }{2}}t^{2}$ ] - $m{\operatorname {d^{2}} \!x \over \operatorname {d} \!t^{2}}+kx=I\delta (t)$ ^[14]

[ ${\frac {\pi }{2}}t^{2}$ ] - $H(x)=\int _{-\infty }^{x}{\delta (t)}\mathrm {d} t$

[ ${\frac {\pi }{2}}t^{2}$ ] - ${\mathcal {F}}(\delta (t-a))=\int _{-\infty }^{\infty }\delta (t-a)e^{-i\omega t}dt=e^{-i\omega a}$ .

[ ${\frac {\pi }{2}}t^{2}$ ] - $\delta (x-\alpha )={\frac {1}{2\pi }}\int _{-\infty }^{\infty }e^{ip(x-\alpha )}\ dp\ .$

[ ${\frac {\pi }{2}}t^{2}$ ] - $\delta (x)=\lim _{\epsilon \to 0}\;{\frac {d}{dx}}\;U(\epsilon ,x)$

[ ${\frac {\pi }{2}}t^{2}$ ] $\Delta (x)=\sum _{n=-\infty }^{\infty }\delta (x-n),$