Question #49284 Trigonometry Trigonometric Identities and Equations Proving Identities 1 Answer P dilip_k Nov 17, 2016 1−(sin2x1+cosx+1+cosxsinx−sinx1−cosX) =1−((1−cosx)(1+cosx)1+cosx+1+cosxsinx−sinx(1+cosx)(1−cosx)(1+cosx)) =1−1+cosx−1+cosxsinx+sinx(1+cosx)1−cos2x =cosx−1+cosxsinx+sinx(1+cosx)sin2x =cosx−1+cosxsinx+1+cosxsinx =cosx Answer link Related questions What does it mean to prove a trigonometric identity? How do you prove cscθ×tanθ=secθ? How do you prove (1−cos2x)(1+cot2x)=1? How do you show that 2sinxcosx=sin2x? is true for 5π6? How do you prove that secxcotx=cscx? How do you prove that cos2x(1+tan2x)=1? How do you prove that 2sinxsecx(cos4x−sin4x)=tan2x? How do you verify the identity: −cotx=sin3x+sinxcos3x−cosx? How do you prove that tanx+cosx1+sinx=secx? How do you prove the identity sinx−cosxsinx+cosx=2sin2x−11+2sinxcosx? See all questions in Proving Identities Impact of this question 1578 views around the world You can reuse this answer Creative Commons License