found another way to draw symbol in EJS thanks to  Rocket Car on an Inclined Plane Model
written by Wolfgang Christian, Francisco Esquembre, and Mario Belloni

I look at the source code and realise how they implement:

[quote]$\\beta$[/quote]                 by changing beta to gamma , alpha , theta

interesting huh?

for your info

BTW the text $\\beta$
dollarsign\\betadollarsign cannot display