(cosec θ−cot θ)2 = ?
(a) 1+cos θ1−cos θ (b) 1−cos θ1+cos θ (c) 1+sin θ1−sin θ (d) none of these
(cosec θ−cot θ)2
=cot2θ−2cotθcosecθ+cosec2θ
=cos2θsin2θ−2(cosθsinθ)(1sinθ)+1sin2θ
=cos2θsin2θ−2cosθsin2θ+1sin2θ
=(cos2θ−2cosθ+1)sin2θ
=(1−cosθ)2(1−cos2θ)
=(1−cosθ)2(1+cosθ)(1−cosθ)
=(1−cosθ)(1+cosθ)