Questions in inv-trig

Select	Question
	$2{{\sin }^{-1}}\frac{3}{5}+{{\cos }^{-1}}\frac{24}{25}=$
	$\cos \left[ {{\tan }^{-1}}\frac{1}{3}+{{\tan }^{-1}}\frac{1}{2} \right]=$
	${{\tan }^{-1}}x+{{\cot }^{-1}}(x+1)=$
	${{\cot }^{-1}}\frac{xy+1}{x-y}+{{\cot }^{-1}}\frac{yz+1}{y-z}+{{\cot }^{-1}}\frac{zx+1}{z-x}=$
	If ${{\tan }^{-1}}\frac{a+x}{a}+{{\tan }^{-1}}\frac{a-x}{a}=\frac{\pi }{6}$,then ${{x}^{2}}$=
	If ${{\cos }^{-1}}\frac{3}{5}-{{\sin }^{-1}}\frac{4}{5}={{\cos }^{-1}}x,$then $x =$
	${{\cot }^{-1}}3+\text{cose}{{\text{c}}^{-1}}\sqrt{5}$=
	${{\tan }^{-1}}\frac{1-{{x}^{2}}}{2x}+{{\cos }^{-1}}\frac{1-{{x}^{2}}}{1+{{x}^{2}}}=$
	If ${{\tan }^{-1}}(x-1)+{{\tan }^{-1}}x+{{\tan }^{-1}}(x+1)={{\tan }^{-1}}3x$,then x =
	If ${{\cos }^{-1}}x+{{\cos }^{-1}}y=2\pi ,$then ${{\sin }^{-1}}x+{{\sin }^{-1}}y$is equal to