Integrating Exponential Functions with Sinusoidal Factors

firenze
Messages
5
Reaction score
0
Find the two integrals:
\int_0^{\infty}\frac{e^{-\alpha x^2}}{x^2+1}\sin(\alpha x) \, dx
\int_0^{\infty}e^{-\beta^2t}\cos(\beta x) \, d\beta

Any hint?
 
Physics news on Phys.org
firenze said:
Find the two integrals:
\int_0^{\infty}\frac{e^{-\alpha x^2}}{x^2+1}\sin(\alpha x) \, dx
\int_0^{\infty}e^{-\beta^2t}\cos(\beta x) \, d\beta

Any hint?

As you have not provided any of your own work, that is all I can give. You should have some kind of book or lists with definition of some ways to perform integration, such as reverse chain rule, u substitution, integration by parts and so on.

Which one(s) can you apply here?
 
Or complex integration ?


marlon
 
parts + substitution
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top