2+2=4

Joe is so proud of himself being smarter than everyone...has to rub it in at every turn. BUT HE CANT READ L337!!!!
 
I think that's all mumbo jumbo. 3/3, 5/5, 7/7, 9/9, and 11/11 all equal 1. Therefore that equation says sinX=X-X+X-X+X-X, or sinX=0.

Edit: Unless the ! is pertaining to the bottom number in each fraction, in which case I have no fucking clue whether the equation is valid or not.