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## Main Question or Discussion Point

It's quite a "strange" thing..why people have so many difficulties with dealing with integrals of the form:

[tex] \int _{c-i\infty}^{c+i\infty}dsf(s)e^{st}=I(t) [/tex] ?

You can always make the change of variable s=c+ix so you get:

[tex] \int _{-\infty}^{+\infty}dxf(c+ix)e^{ixt}=I(t)e^{-ict} [/tex] (2)

And (2) is just simply an improper integral that can be evaluated approximately by some quadrature formula..... :approve :

[tex] \int _{c-i\infty}^{c+i\infty}dsf(s)e^{st}=I(t) [/tex] ?

You can always make the change of variable s=c+ix so you get:

[tex] \int _{-\infty}^{+\infty}dxf(c+ix)e^{ixt}=I(t)e^{-ict} [/tex] (2)

And (2) is just simply an improper integral that can be evaluated approximately by some quadrature formula..... :approve :

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