Question

If f(x)=2x-4 then find f^-1(x)

Answer 1

solve the equation for x
f(x)=2x-4
y=2x-4
y+4=2x
\[\frac{y+4}{2}=x\]
switch your x's and y's
\[y=\frac{x+4}{2}\]
\[f^{-1}(x) =\frac{x+4}{2}\]