# Math Help - Inverse of a step function

1. ## Inverse of a step function

Find ƒ–1(x) when ƒ(x) = [x].
Thanks.

2. If the step function is a set of horizontal line segments (looking like "steps" without the risers), there then cannot be an inverse function, because the step function fails the Horizontal Line Test.

There will be an inverse, but it will be a relation containing a set of vertical line segments. And vertical lines are not functions.

3. Of course. I completely forgot about the Horizontal Line Test. Thanks!