Mathematics

Problem

The function

f:\mathbb R\setminus\{-2\}\to\mathbb R

is defined by

f(x)=\frac{mx+1}{x+2},

where

m

is a real parameter. For

f

to be invertible (i.e. one–one and onto its range) on the given domain,

m

must satisfy a)

m=\dfrac12

m>\dfrac12

m\neq\dfrac12

m<\dfrac12