1 | initial version |
It could equally well return -pi/2
:
sage: arctan(+Infinity)
1/2*pi
sage: arctan(-Infinity)
-1/2*pi
The limit as x -> pi/2
is undefined, because the limits from above and below are not equal:
sage: limit(arctan(tan(x)),x=pi/2)
und
sage: limit(arctan(tan(x)),x=pi/2,dir='+')
-1/2*pi
sage: limit(arctan(tan(x)),x=pi/2,dir='-')
1/2*pi