Hi Nico,

Firstly, thanks for the effort in designing the nice questions! I would like to ask about +Quaterions_Rotation question, because of normalizing $k to get $u, the answer that the students need to enter is a decimal approximation. Are you looking to make that exact, or will you add tolerance so the student just enters correct to a number of decimal places?

I think the exact answers make more sense, so I would suggest putting certain variables in quotation marks or evaluating them using maple calls:

$length='sqrt($kx^2+$ky^2+$kz^2)';

.... $angle='$angledeg*Pi/180';