A function whose value decreases more quickly than any polynomial is said to be an exponentially decreasing function. The prototypical example is the function 
,
plotted above.
Exponentially Decreasing Function
See also
Exponential Function, Exponentially Increasing Function, Logarithmically Decreasing Function, Logarithmically Increasing FunctionExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Exponentially Decreasing Function." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ExponentiallyDecreasingFunction.html