5m Zen
( 2
( 2 pictures 5
Home
( 2
( 2 tan (x/2))/(1+tan^2(x/2))
( 2 1 ) 2 in expanded form
( 2 3 ) 2
( 2 u221216 ) 2
( 2 1 ) 4
( 2 1 ) 3
