Question

Establish the following identity: CosA/1-TanA + SinA/1-CotA = CosA-SinA

Answer 1

cosA/(1-tanA) + sinA/(1-cotA)
cosA/(1-tanA) + sinAtanA/(tanA-1)
(cosA - sinAtanA)/(1-tanA)
(cos^2A-sin^2A) / cosA(1-tanA)
(cos^2A-sin^2A)/(cosA-sinA)
cosA+sinA

sure you don't have a typo somewhere?