without expanding, prove that :- (row wise) |(cosec2 θ cot2 θ 1) (cot2 θ cosec2 θ -1) (42 40 2)| = 0 Share with your friends Share 4 Jasleen Kaur answered this Dear Student,We have,Let ∆ = cosec2θcot2θ1cot2θcosec2θ-142402Apply, C1→C1-C2-C3∆ = cosec2θ-cot2θ-1cot2θ1cot2θ-cosec2θ+1cosec2θ-142-40-2402Now, 1+cot2θ=cosec2θ∆=cosec2θ-cosec2θcot2θ1cosec2θ-cosec2θcosec2θ-10402∆=0cot2θ10cosec2θ-10402We know that, If all the elements of any particular row or any particular column are zero then the value of the determinant is also zero.As coloumn 1 consists of only zero.Therefore, ∆=0.Regards 10 View Full Answer