{"action":"opened","issue":{"url":"https://api.github.com/repos/sympy/sympy/issues/8849","labels_url":"https://api.github.com/repos/sympy/sympy/issues/8849/labels{/name}","comments_url":"https://api.github.com/repos/sympy/sympy/issues/8849/comments","events_url":"https://api.github.com/repos/sympy/sympy/issues/8849/events","html_url":"https://github.com/sympy/sympy/issues/8849","id":54793594,"number":8849,"title":"Closed Integral and Fourier Transform","user":{"login":"Nodragem","id":10520249,"avatar_url":"https://avatars.githubusercontent.com/u/10520249?v=3","gravatar_id":"","url":"https://api.github.com/users/Nodragem","html_url":"https://github.com/Nodragem","followers_url":"https://api.github.com/users/Nodragem/followers","following_url":"https://api.github.com/users/Nodragem/following{/other_user}","gists_url":"https://api.github.com/users/Nodragem/gists{/gist_id}","starred_url":"https://api.github.com/users/Nodragem/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Nodragem/subscriptions","organizations_url":"https://api.github.com/users/Nodragem/orgs","repos_url":"https://api.github.com/users/Nodragem/repos","events_url":"https://api.github.com/users/Nodragem/events{/privacy}","received_events_url":"https://api.github.com/users/Nodragem/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-01-19T17:52:33Z","updated_at":"2015-01-19T17:52:33Z","closed_at":null,"body":"Hi,\r\n\r\nwhen i do:\r\n```` python\r\ngaussian = E** (- abs(x)) /2\r\nfourier_transform(gaussian, x, k)\r\n```\r\nI get:\r\n``` python\r\n>>> 1 / (4*pi**2 * k**22 + 1)\r\n```\r\n\r\nwhich is what I expected.\r\n\r\nHowever, when I try to find the Fourier transform from the actual Fourier equation:\r\n\r\n``` python\r\nexpr = E**(-2*pi*I*k*x) * E** (- abs(x)) /2\r\nexp.expand().integrate(x)\r\n```\r\nit returns:\r\n``` python\r\n>>> Integral(exp(-I*k*x)*exp(-Abs(x))/2, x)\r\n```\r\nWhich is right but I would expect sympy to have found the simplified from: 1/(4*pi**2 * k**2 + 1)\r\n\r\nIs it me who don't use sympy properly?\r\n\r\nEDIT:\r\nI actually just realised that the problem could come from the fact I use an undefined integral:\r\nhttp://en.wikipedia.org/wiki/Gaussian_integral\r\n"}}