If \(\ \mathbf{A}+\mathbf{B}+\mathbf{C}=\frac{\pi}{2} \) then

\(\ \tan \mathrm{A} \tan \mathrm{B}+\tan \mathrm{B} \tan \mathrm{C}+\tan \mathrm{C} \tan \mathrm{A}=1\)

\(\ \cot \mathrm{A}+\cot \mathrm{B}+\cot \mathrm{C}=\cot \mathrm{A} \cot \mathrm{B} \cot \mathrm{C} \)

\(\ \cos 2 A+\cos 2 B+\cos 2 C=1+4 \sin A \sin B \sin C \)

All three are correct