One advice : and since ,
One knows that from and , tan(t) is strictly increasing (from - infinity to + infinity). So it has only one solution if you want to solve tan(t)=...
Try for x=0.
Huh ? Isn't ? (if f is a bijection ^-^)(b) Find f(f -1(8)).
And it will be very hard to find itI'm having a tough time finding the inverse.