/1 - cos(x)\ lim |----------| x->oo| 2 | \ sin (x) /
Limit((1 - cos(x))/sin(x)^2, x, oo, dir='-')
/1 - cos(x)\ lim |----------| x->0+| 2 | \ sin (x) /
1/2
= 0.5
/1 - cos(x)\ lim |----------| x->0-| 2 | \ sin (x) /
0.5