Inverse Trigono...

$$\tan^{1}x + \tan^{1}y + \tan^{1}z = \dfrac {\pi}{2}$$, then 

If  $$3\tan^{-1}(\dfrac{1}{2+\sqrt{3}})-\tan^{-1}\dfrac{1}{x}=\dfrac{1}{3}$$, then x is equal to

If  $$cot^{-1}(\sqrt{\cos a})- tan^{-1}(\sqrt{\cos a})=x$$, then $$\sin x$$ is  

The value of $$\underset{|x|\rightarrow\infty}{lim}cos(tan^{-1}(sin(tan^{-1}x)))$$  is equal to

The domain of the function $$\cos ^{-1}(2x-1)$$ is

If $$\cos \left(\sin ^{-1}\dfrac{2}{5} + \cos ^{-1} x\right)=0$$ then $$x$$ is equal to

The value of $$\sin [2 \tan ^{-1} (.75)]$$ is equal to

The value of $$\cos ^{-1} \left(\cos \dfrac{3 \pi}{2}\right)$$ is equal to

If $$\cos ^{-1} \alpha +\cos ^{-1} \beta +\cos ^{-1} \gamma = 3 \pi$$, then $$\alpha (\beta + \gamma) + \beta (\gamma + \alpha) + \gamma (\alpha + \beta)$$

The value of $$\cot \left[cos^{-1}\left(\dfrac{7}{25}\right)\right]$$ is