Parabolas can be the only conic sections that are considered functions because they pass the vertical line test. We have worked with parabolas before in quadratic equations, but parabolas formed by conic sections are a little different.
Toilet drainage rough-in steps. 1  Cut a hole in the subfloor just large enough for the bottom part of the toilet flange to sit. 2  If your installing the drainage underground, excavate the trench and have a supply of clean backfill ready (sand or gravel) to grade and cover the pipe.
Install a toilet flange by pushing the pipe through the floor and setting the metal or plastic ring on the subfloor. The top of the ring should be flush with the surface of the finished floor. Screw or bolt the flange to the subfloor.