Question

If the function f(x) = mx + b has an inverse function, what must be true about it?

Answer 1

hi!
it has an inverse because it is a one to one function (because it is a line)

Answer 2

not really clear why they are saying "if" it has an inverse
it does have an inverse
the inverse is
\[f^{-1}(x)=\frac{x-b}{m}\]