A curve $y=f\left(x\right)$  is defined parametrically as $x=\frac{1-t^2}{1+t^2},y=\frac{2t}{1+t^2}$  then _____.

Area founded by $y=f\left(x\right)$  is  $\pi$ sq.u

Area founded by   $y=f\left(x\right)$ with normal at any point on it is  $\frac{\pi }{2}$sq.u

Area founded by  $y=f\left(x\right)$,  $y=\sqrt{3}x$ with x-axis is  $\frac{\pi }{3}sq.u$

Area founded by  $y=f\left(x\right)$, $y=\sqrt{3}x$ and x-axis is $\frac{\pi }{6}sq.u$