If sin(y+z−x),sin(z+x−y),sin(x+y−z) are in A.P., then tan x, tan y, tan z are in
A.P
G.P
H.P
none of these
Applying b- a= c-b for A.P., we get
2coszsin(x−y)=2cosxsin(y−z)
Dividing by 2 cosx cosy cosz, etc., we get
tanx-tany = tany-tanz