If [tan–1x]2 – 2[tan–1x] + 1 ≤ 0, where [.] denotes greatest integer ≤ x, x belongs to
[tan1, tan2)
π4,π2
[tan1,∞)
none of these
The given inequation is[[tan–1 x] – 1]2 ≤ 0⇒ [tan–1x]= 1 as [[tan–1x]– 1]2 ≮ 0⇒ 1 ≤ tan–1x < 2⇒ x ∈[tan 1, tan 2)