If tanβ=2sinαsinγcosec(α+γ) then cotα,cotβ,cotγ are in
A.P
G.P.
H.P
none of these
tanβ=2sinαsinγcosec(α+γ)=2sinαsinγsin(α+γ)
or cotβ=sin(α+γ)2sinαsinγor 2cotβ=sinαcosγ+cosαsinγsinαsinγ=cotα+cotγ
or cotα,cotβ,cotγ are in A.P.