2. ????????????^−????(???????????? ^????????)

First settle for, tan 7???? = tan(???? + ????) = tan ????

Presently: ????????????−1(tan 7????) = tan−1(tan ????) = ???? ∈ (- π/2, π/2)

[As tan-1 tan(x) = x if x ∈ (- π/2, π/2) ]

So the worth of ????????????−1(tan 7????) is ????.