How do you verify the identity (tanx+tany)/(1-tanxtany)=(cotx+coty)/(cotxcoty-1)? Trigonometry Trigonometric Identities and Equations Proving Identities 1 Answer Bdub Apr 19, 2017 see below Explanation: Right Hand Side: color(blue)((cot x+cot y)/(cot xcoty-1)=color(red)((1/tanx + 1/tany)/(1/tanx * 1/tany -1 color(red)(=((tany+tanx)/(tanxtany))/((1-tanxtany)/(tanx tany) color(red)(=(tany+tanx)/(tanxtany) *(tanx tany)/ (1-tanxtany) color(red)(=(tany+tanx)/cancel(tanxtany) *cancel(tanx tany)/ (1-tanxtany) color(red)(=(tany+tanx)/ (1-tanxtany) color(red)(=(tanx+tany)/ (1-tanxtany) color(red)(= Left Hand Side Answer link Related questions What does it mean to prove a trigonometric identity? How do you prove \csc \theta \times \tan \theta = \sec \theta? How do you prove (1-\cos^2 x)(1+\cot^2 x) = 1? How do you show that 2 \sin x \cos x = \sin 2x? is true for (5pi)/6? How do you prove that sec xcot x = csc x? How do you prove that cos 2x(1 + tan 2x) = 1? How do you prove that (2sinx)/[secx(cos4x-sin4x)]=tan2x? How do you verify the identity: -cotx =(sin3x+sinx)/(cos3x-cosx)? How do you prove that (tanx+cosx)/(1+sinx)=secx? How do you prove the identity (sinx - cosx)/(sinx + cosx) = (2sin^2x-1)/(1+2sinxcosx)? See all questions in Proving Identities Impact of this question 21439 views around the world You can reuse this answer Creative Commons License