f is a continous function at R, which gets a local maximum at x0. i need to prove that if f doesn't have any other extremas, so f gets a maximum at x0 (CLUE: USE WEIERSTRASS THEOREM)
this is a very easy question...go here
Extreme value theorem - Wikipedia, the free encyclopedia
and find the answer
instinctively i know it's true, and i can see it's probably an easy question...
but, even after i read (it's not that easy to me to read math wikipedia values in english) the link, i don't know how to formulate proof for that (using this theorem)...