To solve this problem you must apply the proccedure shown below. You have that:
1+cot^2θ=csc^2θ (You have that cos^2θ+sin^2θ=1)<span> 1+(cos^2</span>θ/sin^2θ)=csc^2θ 1+(1-sin^2θ/sin^2θ)csc^2θ sin^2θ+1-sin^2θ=csc^2θ 1/sin^2=csc^2 (You have that 1/sin=csc)