LHS = \(\cfrac{tan\,\text x}{1-cot\,\text x}+\cfrac{cot\text x}{1-tan\,\text x}\)
We know that tan θ = \(\cfrac{sin \,\theta}{cos\,\theta}\) and cot θ = \(\cfrac{cos\,\theta}{sin\,\theta}\)
We know that a3 - b3 = (a - b) (a2 + b2 + ab)
We know that sin2x + cos2x = 1.
We know that cosec θ = \(\cfrac1{sin \,\theta}\); sec θ = \(\cfrac1{cos \,\theta}\)
= cosecx × secx + 1
secx cosecx + 1
= RHS
Hence proved.