If (1+i1−i)m=1, then the least integral value of m is [IIT 1982; MNR 1984; UPSEAT 2001; MP PET 2002]
If (1+i1−i)m = 1 then the least integral value of m is
If tan A = - 12 and tan B = - 13, then A + B =
[IIT 1967; MNR 1987; MP PET 1989]