If are positive reals with and . Find the maximum value of the expression above.
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
We have
a ≥ b ≥ c a + c ≥ b + c ≥ 2 c ⟹ a + c ≥ b + c b + c 1 ≥ a + c 1 ⟹ a + c ≥ 2 c 2 c 1 ≥ a + c 1 ⟹ b + c ≥ 2 c b + c 1 ≥ 2 c 1
From these have two sets
a ≥ b ≥ c 2 c 1 ≥ b + c 1 ≥ c + a 1
Using Rearrangement Inequality,
2 c a + b + c b + c + a c ≥ b + c a + c + a b + 2 c c 2 1 7 − 2 1 ≥ b + c a + c + a b 8 ≥ b + c a + c + a b
Hence the maximum value is 8