If θ=2π7, then the value of tan θ tan 2θ+ tan 2θ tan 4θ+tan 4θ tan θ is
If tan θ, 2 tan θ + 2, 3 tan θ + 3 are in G.P. then the value of 7−5 cot θ9−4 √sec2 θ−1 is
If θ is an acute angle and, tanθ + cotθ = 2 then the value of tan7θ + cot7θ is