fx=x-1x+1x fx+fx=x-1xfx-1=-1-fxx=1+fx1-fxreplace x by f-1xf-1x=1+ff-1x1-ff-1xf-1x=1+x1-x For remaining queries, post them in a new thread

please do it

f (x) = \frac{x - 1}{x + 1} x f (x) + f (x) = x - 1 x (f (x) - 1) = - 1 - f (x) x = \frac{1 + f (x)}{1 - f (x)} r e p l a c e x b y f^{- 1} (x) f^{- 1} (x) = \frac{1 + f (f^{- 1} (x))}{1 - f (f^{- 1} (x))} f^{- 1} (x) = \frac{1 + x}{1 - x}

For remaining queries, post them in a new thread