What is 1+cosx1+secx for x=π3? Trigonometry Trigonometric Identities and Equations Proving Identities 1 Answer Shwetank Mauria Jan 2, 2017 1+cosx1+secx=cosx and for x=π3, it is 12. Explanation: 1+cosx1+secx = 1+cosx1+1cosx = 1+cosxcosx+1cosx = (1+cosx)×cosx1+cosx = cosx Hence 1+cosx1+secx=cosx for all values of x and for x=π3 1+cosx1+secx=1+cos(π3)1+sec(π3) = 1+121+2=323=32×13=12 As cosx=cos(π3)=12 for x=π3, 1+cosx1+secx=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 1334 views around the world You can reuse this answer Creative Commons License