In the Photos app, you'll find "Recently Deleted" when your software is up to date (iOS 8x). The photos there don't show up as an extra entry in your storage space. They can be recovered as long as you don't remove them from there, so make sure you delete these to when you don't need them any more.
There's no trash on the iPad. When you've deleted the photos from that folder as well, they're gone and also can't be recovered.
If your running an earlier software, your photos will be gone as soon as you remove them from the Photos app. There's no Recently Deleted folder in the app.