Skip to main content
2 of 2
added 92 characters in body
Alexandre Eremenko
  • 91.8k
  • 9
  • 259
  • 429

For real functions whose domain is a real interval, it is necessary and sufficient that the second derivative is a function of bounded variation on every compact interval in the domain. Or, in terms of distributions, the second derivative must be a measure (a difference of two non-negative measures).

Alexandre Eremenko
  • 91.8k
  • 9
  • 259
  • 429