Let \[f:N \to Y\] be a function defined as f(x) = 4x + 3 where
Y = { y \[ \in \] N, y = 4x + 3 for some x \[ \in \] N }.
Show that f is invertible and its inverse is
Solutions · 1
Official solution
Clearly f is one one and onto, so invertible
Also \[f\left( x \right) = 4x + 3 = y \Rightarrow x = {{y - 3} \over 4}\]
\[\therefore\] \[\,\,\,\,g\left( y \right) = {{y - 3} \over 4}\]