How do you prove #(sin x+ 1) / (cos x + cot x) = tan x#? Trigonometry Trigonometric Identities and Equations Proving Identities 1 Answer Lucy Jun 23, 2018 Below Explanation: #(sinx+1)/(cosx+cotx)=tanx# LHS #(sinx+1)/(cosx+cotx)# =#(sinx+1)/(cosx+cosx/sinx)# =#(sinx+1)/((sinxcosx+cosx)/sinx)# =#(sinx^2+sinx)/(sinxcosx+cosx)# =#(sinx(sinx+1))/(cosx(sinx+1))# =#(sinx cancel((sinx+1)))/(cosx cancel((sinx+1)))# =#sinx/cosx# =#tanx# =RHS Therefore, #(sinx+1)/(cosx+cotx)=tanx# 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 9487 views around the world You can reuse this answer Creative Commons License