Questions in inv-trig

Select	Question
	$2{{\tan }^{-1}}\left( \frac{1}{3} \right)+{{\tan }^{-1}}\left( \frac{1}{7} \right)=$
	${{\cos }^{-1}}\left( \frac{15}{17} \right)+2{{\tan }^{-1}}\left( \frac{1}{5} \right)=$
	${{\sin }^{-1}}\left( \frac{3}{5} \right)+{{\tan }^{-1}}\left( \frac{1}{7} \right)=$
	A solution of the equation ${{\tan }^{-1}}(1+x)$ $+{{\tan }^{-1}}(1-x)$ $=\frac{\pi }{2}$ is
	If ${{x}^{2}}+{{y}^{2}}+{{z}^{2}}={{r}^{2}}$, then ${{\tan }^{-1}}\left( \frac{xy}{zr} \right)+$ ${{\tan }^{-1}}\left( \frac{yz}{xr} \right)+\tan \left( \frac{zx}{yr} \right)=$
	The greatest and the least value of ${{({{\sin }^{-1}}x)}^{3}}+{{({{\cos }^{-1}}x)}^{3}}$are
	If $a<\frac{1}{32},$ then the number of solution of ${{({{\sin }^{-1}}x)}^{3}}+{{({{\cos }^{-1}}x)}^{3}}=a{{\pi }^{3}}$ is
	If $k\le {{\sin }^{-1}}x+{{\cos }^{-1}}x+{{\tan }^{-1}}x\le K,$then
	If ${{({{\tan }^{-1}}x)}^{2}}+{{({{\cot }^{-1}}x)}^{2}}=\frac{5{{\pi }^{2}}}{8},$then $x$ equals
	If $\tan (x+y)=33$and $x={{\tan }^{-1}}3,$then y will be