Without using trigonometrical tables please prove the following sum. I want the answer by tmrw morning. Q. Prove without using sin 90 - θ . sin θ tan θ - 1 ⇒ – sin 2 θ Share with your friends Share 0 Rishabh Mittal answered this Dear Student, LHSsin 90-θ . sin θtan θ-1=cos θ sin θsin θcos θ - 1=cos2θ - 1=- sin2θ=RHSHence Proved Regards 1 View Full Answer