If tan A = - 12 and tan B = - 13, then A + B =
[IIT 1967; MNR 1987; MP PET 1989]
π4
3π4
5π4
None of these
We have tan A = - 12 and tan B = - 13
Now, tan(A + B) = tanA+tanB1−tanAtanB = −12−131−12.13 = -1
⇒ tan(A + B) = tan 3π4. Hence, A + B = 3π4.