how can i do?
For a,b,c real positive numbers, show that ;
(a+b+c)(1/a + 1/b + 1/c)>= 9
is there any theorem to use?
i dont know theorems based on this..
can u help me with this?
You could start with
.
Then,
are positive numbers).
So, multiply out the LHS of your inequality and collect up terms. The two terms involving can be combined to produce the fraction , so you can make use of the result obtained earlier.
Do the same for the terms involving and those involving , and the result follows.