If A , B , C are in arithmetic progression and B = π 4 , then tan ⁡ A tan ⁡ B tan ⁡ C =

Step-by-step solution

∵ Angles A , B , C are in arithmetic progression and ∠ B = π 4 then A = π 4 - θ C = π 4 + θ Hence tan ⁡ π 4 - θ tan ⁡ π 4 tan ⁡ π 4 + θ = 1 - tan ⁡ θ 1 + tan ⁡ θ . 1 . 1 + tan ⁡ θ 1 - tan ⁡ θ = 1