Questions in differentiation

Select	Question
	If $y={{\sin }^{-1}}\frac{2x}{1+{{x}^{2}}},$where $0
	$\frac{d}{dx}{{\tan }^{-1}}\frac{x}{\sqrt{{{a}^{2}}-{{x}^{2}}}}=$
	$\frac{d}{dx}{{\cos }^{-1}}\sqrt{\frac{1+{{x}^{2}}}{2}}=$
	$\frac{d}{dx}{{\tan }^{-1}}\left[ \frac{3{{a}^{2}}x-{{x}^{3}}}{a({{a}^{2}}-3{{x}^{2}})} \right]$at $x=0$is
	If $\sqrt{1-{{x}^{2}}}+\sqrt{1-{{y}^{2}}}=a(x-y)$, then $\frac{dy}{dx}=$
	$\frac{d}{dx}{{\sin }^{-1}}(2ax\sqrt{1-{{a}^{2}}{{x}^{2}}})=$
	$\frac{d}{dx}\left\{ {{\cos }^{-1}}\left( \frac{1-{{x}^{2}}}{1+{{x}^{2}}} \right) \right\}=$
	If $y={{\sin }^{-1}}\sqrt{1-{{x}^{2}}}$, then $dy/dx=$
	The differential coefficient of ${{\cos }^{-1}}\left\{ \sqrt{\frac{1+x}{2}} \right\}$with respect to x is
	If $y={{\tan }^{-1}}\sqrt{\frac{a-x}{a+x}}$, then $\frac{dy}{dx}=$