sin3⁡θ−cos3⁡θsin⁡θ−cos⁡θ−cos⁡θ1+cot2⁡θ−2tan⁡θcot⁡θ=−1 if

sin2⁡θ+cos2⁡θ+sin⁡θcos⁡θ−cos⁡θ|cosec⁡θ|−2=−1or  1+sin⁡θcos⁡θ−|sin⁡θ|cos⁡θ−1=0or  cos⁡θ(sin⁡θ−|sin⁡θ|)=0⇒ θ∈0,π2 or θ∈π2,πBut θ≠π4    (not in domain);Therefore θ∈π2,π