If msinθ=n sin(θ+2α),provethattan(θ+α)cotα=m+nm−n
Given that msinθ=n sin(θ+2α)∴sin(θ+2α)sinθ=mn
Using componendo and dividendo, we get
sin(θ+2α)+sinθsin(θ+2α)−sinθ=m+nm−n⇒2sin(θ+2α+θ2)cos(θ+2α−θ2)2cos(θ+2α+θ2)sin(θ+2α−θ2)=m+nm−n[∵ sin x+siny=2sinx+y2cosx−y2 and sinx−siny=2cosx+y2sinx−y2]⇒sin(θ+α)cosαcos(θ+α)sinα=m+nm−n⇒tan(θ+α)cotα=m+nm−n