# RegionPlot example in documentation fails

Bug introduced in 10.4 and fixed in 11.0

I am running Mathematica 10.4.1.0 on a MacBook Pro OSX 10.11.5. I opened the documentation for TransformedRegion, went to this example in Scope > Formula Regions. When I open this particular documentation, the image is present, but when I ran these two lines:

pr = ParametricRegion[{Sin[θ], Sin[2 θ]}, {{θ, 0, 2 π}}]
RegionPlot[pr]


I got a blank image:

I've tried quitting the kernel and I've tried restarting Mathematica, but it still doesn't work.

Anyone else experiencing this?

• Yep, same here on Windows. Also the first basic example for ParametricRegion fails. – Simon Woods Jun 26 '16 at 21:08
• I seem to have the same problem. The example given in Mathematica help ParametricRegion[{Cos[t], Sin[t]}, {{t, 0, 2 Pi}}]] also fails (Mathematica 10.4.1, 64-bit Linux) – mikado Jun 26 '16 at 21:09
• Curiously it works if I replace 2 Pi with 6.28 – Simon Woods Jun 26 '16 at 21:12
• OK. I'll report this to Wolfram. – David Jun 26 '16 at 21:30
• and works with 1.9999999 Pi ... – Young Jun 26 '16 at 21:37