Let f be a function. If any horizontal line intersects the graph of f more than once, then f does not have an inverse. An absolute value function (without domain restriction) has an inverse that is NOT a function. That's why an absolute value function does not have an inverse function。
a speed run is technically Speed work refers to a type of running workout in which you are running for certain intervals near, at, or even faster than your VO2max pace.
