Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Thank you for your answer. But, I cann't still understand the meaning of this sentence of $\|\nabla f\|$ is not bounded away from zero". Is $\|\nabla f\|>0$ no bounded below, and verge to 0?
Thank you for your answer. But, I cann't still understand the meaning of this sentence of $\|\nabla f\|$ is not bounded away from zero". – unknown (yahoo) 0 secs ago
