This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Paraboloid. Gerenderter Paraboloid made with Povray german Lars Rohwedder RokerHRO Created with Persistence of Vision RokerHRO Elliptic paraboloids Created with Persistence of Vision
Page 2023 Free-images.com. All images are Public Domain