MHB Can the Inequality $x,y,z>1$ be Proven with a Hint of 48?

  • Thread starter Thread starter Albert1
  • Start date Start date
  • Tags Tags
    Inequality Proof
Click For Summary
The discussion revolves around proving the inequality involving positive variables x, y, and z, each greater than 1. The specific inequality to be proven is that the sum of the fractions, $\dfrac{x^4}{(y-1)^2}+\dfrac{y^4}{(z-1)^2}+\dfrac{z^4}{(x-1)^2}$, is greater than or equal to 48. Participants are encouraged to explore the hint provided, which suggests a potential method or insight for the proof. The focus remains on finding a rigorous mathematical approach to establish the inequality under the given conditions. The conversation emphasizes the need for clarity in the proof process and the importance of the hint in guiding the solution.
Albert1
Messages
1,221
Reaction score
0
$x,y,z>1$

please prove :

$\dfrac{x^4}{(y-1)^2}+\dfrac{y^4}{(z-1)^2}+\dfrac{z^4}{(x-1)^2}\geq 48$
 
Last edited:
Mathematics news on Phys.org
Albert said:
$x,y,z>1$

please prove :

$\dfrac{x^4}{(y-1)^2}+\dfrac{y^4}{(z-1)^2}+\dfrac{z^4}{(x-1)^2}\geq 48$
hint:
prove :$\dfrac{x^4}{(y-1)^2}\geq 32(x-y)+16$
 
Albert said:
hint:
prove :$\dfrac{x^4}{(y-1)^2}\geq 32(x-y)+16$
$\dfrac{x^4}{(y-1)^2}+16(y-1)+16(y-1)+16\geq 4\sqrt[4]{16^3x^4}= 32x$
or :$\dfrac{x^4}{(y-1)^2}\geq 32(x-y)+16$
please complete the rest
 
Here is a little puzzle from the book 100 Geometric Games by Pierre Berloquin. The side of a small square is one meter long and the side of a larger square one and a half meters long. One vertex of the large square is at the center of the small square. The side of the large square cuts two sides of the small square into one- third parts and two-thirds parts. What is the area where the squares overlap?

Similar threads

Replies
6
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 2 ·
Replies
2
Views
1K