How do you find a numerical value of one trigonometric function of x given (1+cosx)/sinx+sinx/(1+cosx)=41+cosxsinx+sinx1+cosx=4? Trigonometry Trigonometric Identities and Equations Proving Identities 1 Answer Bdub Nov 12, 2016 :.x=pi/6 +2pin or x=(5pi)/6 +2pin Explanation: (1+cosx)/sinx + sinx/(1+cosx)=4 ((1+cosx)(1+cosx) + sinxsinx)/((1+cosx)sinx)=4 (1+2cosx+cos^2x+ sin^2x)/((1+cosx)sinx)=4 (1+2cosx+1)/((1+cosx)sinx)=4 (2+2cosx)/((1+cosx)sinx)=4 (2(1+cosx))/((1+cosx)sinx)=4 (2cancel(1+cosx))/(cancel(1+cosx)sinx)=4 2/sinx=4 2=4sinx 2/4=sinx 1/2=sinx sin^-1(1/2)=x :.x=pi/6 +2pin or x=(5pi)/6 +2pin 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 16885 views around the world You can reuse this answer Creative Commons License