How do i find integral of this
Welcome to the form.
You look it up in a table or use a CAS.
You will not be able to do it by hand, because there is no closed form in terms of elementary functions.
In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.