-1
$\begingroup$

If the derivative of a function is lipschitz,,,does it mean that the function itself is also lipschitz? Any proof for that?

$\endgroup$
1
  • $\begingroup$ A consequence of the mean value theorem is that the best Lipschitz constant for a derivable function on an interval is equal to the uniform norm of its derivative. $\endgroup$ Commented Sep 21, 2012 at 7:56

1 Answer 1

4
$\begingroup$

No. $f(x)=x^2$ on the whole real line is not Lipschitz, but the derivative $f'(x)=2x$ is. However, if the function is defined on a bounded interval, then the statement is true. Indeed, if $f'$ is Lipschitz, then it is continuous and thus bounded, and a function with bounded derivative is Lipschitz.

$\endgroup$

Not the answer you're looking for? Browse other questions tagged .