Formula is invalid and not ready to execute

ROOT
1

Hi,
running this…

    TF2 *fsphere = new TF2("fsphere","-sqrt([0]^2-(x-[2])^2)+[0]-sqrt([1]^2-(y-[3])2^)+[1]",-60,60,-30,30);
	fsphere->SetParameter(0,1000);
	fsphere->SetParameter(1,2000);
	fsphere->SetParameter(2,0);
	fsphere->SetParameter(3,0);
	fsphere->Draw();

…leads to

Error in <TFormula::Eval>: Formula is invalid and not ready to execute
sqrt is unknown.
TMath::Sq is unknown.
TMath::Sq is unknown.
TMath::Sq is unknown.

any hint?

Thanks
Georg

my environment

root -b -q
   ------------------------------------------------------------------
  | Welcome to ROOT 6.28/06                        https://root.cern |
  | (c) 1995-2023, The ROOT Team; conception: R. Brun, F. Rademakers |
  | Built for win64 on Aug 28 2023, 11:29:15                         |
  | From tags/v6-28-06@v6-28-06                                      |
  | With MSVC 19.32.31332.0                                          |
  | Try '.help'/'.?', '.demo', '.license', '.credits', '.quit'/'.q'  |
   ------------------------------------------------------------------
2

)2^)

3

omg…

I was looking on that for 30min :slight_smile:
working… thanks a lot

Georg