Simplify (1+cos2A+sin2A)/(1-cos2A+sin2A)? Trigonometry Trigonometric Identities and Equations Proving Identities 1 Answer Shwetank Mauria Sep 18, 2016 Please see below. Explanation: (1+cos2A+sin2A)/(1-cos2A+sin2A) Now sin2A=2sinAcosA and cos2A=2cos^2A-1=1-2sin^2A Hence (1+cos2A+sin2A)/(1-cos2A+sin2A) = (1+2cos^2A-1+2sinAcosA)/(1-(1-2sin^2A)+2sinAcosA) = (1+2cos^2A-1+2sinAcosA)/(1-1+2sin^2A+2sinAcosA) = (2cos^2A+2sinAcosA)/(2sin^2A+2sinAcosA) = (2cosA(cosA+sinA))/(2sinA(sinA+cosA)) = (2cosA)/(2sinA) = cotA 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 9736 views around the world You can reuse this answer Creative Commons License