Chứng minh rằng với mọi số thực x,y,z:
$\left | x+y-z \right |+\left | y+z-x \right |+\left | x+z-y \right | \left +| x+y+z \right | \geqslant 2(\left | x \right |+\left | y \right |+\left | z \right |)$
Dấu "=" xảy ra khi nào?
$(\sum \left | x+y-z \right |) + \left | x+y+z \right | \geqslant 2(\sum \left | x \right |)$
Started By RoyalMadrid, 23-11-2013 - 21:53
1 user(s) are reading this topic
0 members, 1 guests, 0 anonymous users
