InĂ©galitĂ© dans un espace vectoriel normĂ© Soient $ (E, \| \cdot \|) $ un evn et $ (a,b,c,d) \in E^4 $. Montrer que: \[\|a-b\| + \|c-d\| \leq \|a-c\| + \|b-d\| + \|a-d\| + \|b-c\| \] đ Solution Available A solution has been written for this exercise. View Solution (Opens in New Tab) â â Back to All Posts