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Matematika => Fisika Matematik => Topik dimulai oleh: trfrm pada Juli 19, 2018, 06:12:12 PM

Judul: The Unit Step Function and The Dirac Delta
Ditulis oleh: trfrm pada Juli 19, 2018, 06:12:12 PM

Excuse me ... .

Can the unit step function,

\[ u(x):=\left\{\begin{array}{ll}1&\textrm{if}~x>0\\0&\textrm{if}~x<0\end{array}\right. ,\]

be approached by the function

\[ v(x):=\displaystyle\lim_{k\rightarrow\infty}\frac{1}{2}\left(1+\tanh{kx}\right) \]

and

\[ w(x):=\displaystyle\lim_{k\rightarrow\infty}\frac{1}{2}\left(1+\frac{2}{\pi}\arctan{kx}\right) \] ... ?

Next ... , can Dirac Delta $\delta(x)$ be approached by $v'(x)$ and $w'(x)$, such that

\[ v'(x):=\frac{dv(x)}{dx} \] and \[ w'(x):=\frac{dw(x)}{dx} \] ... ?

Thank you very much ... . God bless you all ... . 

Judul: Re:The Unit Step Function and The Dirac Delta
Ditulis oleh: trfrm pada Juli 19, 2018, 06:14:20 PM

@ river_rat

I have corrected my post ... . I have made a grammatical mistakes in my post, so my post cannot be understanded ... . I'm sorry very much ... . :(