Inverse Functions
Run the machine backwards.
Concept
Swap and solve
An inverse undoes the original: f⁻¹(f(x)) = x. To find it, write y = f(x), swap x and y, then solve for y.
Graphically, the inverse is the reflection across the line y = x. Only one-to-one functions have true inverses.
y = ax + b ⟹ f⁻¹(x) = (x − b)/a