To find the inverse of the function
f(x) = 4x + 8
First substitute y = f(x) in the above and then solve for x
y = 4x + 8
subtract 8 from both-side of the equation
y - 8 = 4x
Divide both-side of the equation by 4
[tex]x=\frac{y-8}{4}[/tex]Replace x by f⁻'(x) and y by x
That is;
[tex]f^{-1}(x)=\frac{x-8}{4}[/tex]