Question

confirm that (f°g)(x)=(g°f)(x)=x

Answer 1

Hello,

It is enough to prove that g(x)=f(^-1)(x)

f(x): y=(2x+3)/(x+4)

f(^-1): x=(2y+3)/(y+4)
==>xy+4x=2y+3
==>y(x-2)=3-4x
==>y=(3-4x)/(x-2)
==>y=(4x-3)/(2-x)= g(x)