How do you integrate this function (not by parts)?

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SUMMARY

The discussion focuses on integrating the function r² * exp(i*k*r - r²/a²) from -infinity to +infinity. The recommended approach involves completing the square in the exponential term and changing variables to y = r - b, where b is derived from the completed square. The integration can be simplified using known results for Gaussian integrals, leading to substitutions such as z = r/a - (1/2)i*a*k, which facilitate the evaluation of integrals like ∫ e^(z²) and ∫ z e^(z²) without resorting to integration by parts.

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Homework Statement



integrate: r2*exp(i*k*r - r2/a2) from -infinity to +infinity (in terms of r)

Homework Equations



relevant integration table

The Attempt at a Solution



not sure what this function or the method to solve this function is called
 
Last edited:
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I would start by completing the square in the exponential, and then changing variables to y = r - b, where b is whatever you get when you complete the square. Then, use know results for the integrals of Gaussian functions.
 
Without going through the whole exercise, the thing that comes to mind is splitting off a square. I think that eventually you will find a substitution like [itex]z = r/a - \tfrac12 i a k[/itex] which will allow you to write it in terms of integrals like
[itex]\int e^{z^2}[/itex] and [itex]\int z e^{z^2}[/itex]
which you can do without partial integration.
 

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