Bug introduced in 10.0.2 or earlier and persisting through 11.1.0
Note: TransformedRegion was introduced in 10.0.0.
Reproducing an example from [Mathematica's help][1], I obtain an incomplete plot
ClearAll; a = TransformedRegion[Disk[{1, 1}, 4], {Indexed[#, 1] *Indexed[#, 2],
Indexed[#, 1] + Indexed[#, 2]} &];RegionPlot[a]
[![enter image description here][2]][2]
instead of an entire plot. How to fix it? [1]: http://reference.wolfram.com/language/ref/TransformedRegion.html [2]: https://i.sstatic.net/4cdOa.png
