$\cos \tan ^{-1} \sin \cot ^{-1} x=?$

$\sqrt{\frac{1-x^{2}}{1+x^{2}}}$

$\sqrt{\frac{1+x^{2}}{1-x^{2}}}$

$\sqrt{\frac{1-x^{2}}{2+x^{2}}}$

$\sqrt{\frac{1+x^{2}}{2+x^{2}}}$