Let `f: RvecR` be a function given by `f(x)=a x+b` for all `x in R` . Find the constants `aa n db` such that `fof=I_Rdot`

Explanation

`f(x)=ax+b`

So,

`f(f(x))=a(ax+b)+b=x`

`=>(a^2-1)x+ab+b=0`


So,

`a^2-1=0` and `ab+b=0`

`a^2=1` and `b(a+1)=0`

...