 ##  [Point of Non-Differentiability](/point-non-differentiability) 

  ##  [Point of Non-Differentiability](https://mathlogic.quantumdictionary.io/point-non-differentiability-0) 

  
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- Natural &amp; Formal Sciences -

**Mathematics &amp; Logic Dictionary**

 
Definition

A location x0 in the domain of a real- or vector-valued function where the derivative (or differential) does not exist or is not well defined, typically because of a corner, cusp, vertical tangent, or oscillatory behavior that prevents the linear approximation from converging.