Each Part: 2 Marks
(i) LHS=cot A+tan Bcot B+tan A=(1tan A)+tan B(1tan B)+tan A=(1+tan A tan B)tan A×tan B(1+tan A tan B)=cot A tan B=RHS
(ii)LHS=1+tan2 θ1+cot2 θ=sec2 θcosec2 θ=sin2 θcos2 θ=tan2 θRHS=(1−tan θ1−cot θ)2=[1−(sin θcos θ)1−(cos θsin θ)]2=[cos θ−sin θcos θsin θ−cos θsin θ]2=[−(sin θ−cos θ)cos θ×sin θ(sin θ−cos θ)]2=sin2 θcos2 θ=tan2 θ
LHS = RHS