Re: How to recover deleated pic
How recently was the photo deleted? If it was within the last 30 days it may be in the deleted photos album in photos (Open Photos> on the bottom right select Albums> Recently Deleted). If it is there then you can select the photo and recover it. If it is beyond that or was cleared from recently deleted you may have to restore from a backup that had the photo. The second solution is dependent on other variables though such as your iCloud/iTunes backup status, if you where using iCloud Photo Library, how long ago the photo was lost, ect. Beyond that the only other solution I can think of that would be potentially available would be Dropbox or google photos sync, assuming that one of those (or other apps of the sort) were downloaded and active on your device.
I hope that helps!