Prove Inequality Challenge: $x,y,z,w > 0$

In summary, the "Prove Inequality Challenge" is a mathematical problem where you must prove that in a given equation, the values of x, y, z, and w are all greater than 0. To solve it, you need to understand the properties of inequalities, analyze the given equation, and use logical reasoning and mathematical skills. There is no specific method or strategy, but common approaches include algebraic manipulations and proof by contradiction. It is important to only use your mathematical knowledge and skills and not rely on tools or software. To make solving the challenge easier, practice solving different types of inequalities and always double-check your work.
  • #1
Albert1
1,221
0
$x,y,z,w>0$
prove:
$(1+x)(1+y)(1+z)(1+w)\geq (\sqrt[3]{1+xyz}\,\,\,)(\sqrt[3]{1+yzw}\,\,\,)(\sqrt[3]{1+zwx}\,\,\,)(\sqrt[3]{1+wxy}\,\,\,)$
 
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  • #2
Here is my solution:
Since $(1 + a)(1 + b)(1 + c) \ge 1 + abc$ for all $a,b,c\ge 0$, we have

$$(1 + x)(1 + y)(1 + z)(1 + w)$$
$$= \sqrt[3]{(1 + x)(1 + y)(1 + z)}\sqrt[3]{(1 + y)(1 + z)(1 + w)}\sqrt[3]{(1 + z)(1 + w)(1 + x)}\sqrt[3]{(1 + w)(1 + x)(1 + y)}$$
$$\ge \sqrt[3]{1 + xyz}\sqrt[3]{1 + yzw}\sqrt[3]{1 + zwx}\sqrt[3]{1 + wxy},$$

as desired.
 
  • #3
Euge said:
Here is my solution:
Since $(1 + a)(1 + b)(1 + c) \ge 1 + abc$ for all $a,b,c\ge 0$, we have

$$(1 + x)(1 + y)(1 + z)(1 + w)$$
$$= \sqrt[3]{(1 + x)(1 + y)(1 + z)}\sqrt[3]{(1 + y)(1 + z)(1 + w)}\sqrt[3]{(1 + z)(1 + w)(1 + x)}\sqrt[3]{(1 + w)(1 + x)(1 + y)}$$
$$\ge \sqrt[3]{1 + xyz}\sqrt[3]{1 + yzw}\sqrt[3]{1 + zwx}\sqrt[3]{1 + wxy},$$

as desired.
very good !
 

FAQ: Prove Inequality Challenge: $x,y,z,w > 0$

1. What is the "Prove Inequality Challenge?"

The "Prove Inequality Challenge" is a mathematical problem that requires you to prove that in a given equation, the values of x, y, z, and w are all greater than 0. It tests your understanding of mathematical inequalities and your ability to logically prove them.

2. How do I approach the "Prove Inequality Challenge?"

To solve the "Prove Inequality Challenge," you should start by understanding the properties of inequalities and the rules for manipulating them. Then, carefully analyze the given equation and look for any patterns or relationships between the variables. Finally, use logical reasoning and mathematical operations to prove that all values are greater than 0.

3. Is there a specific method or strategy to solve the "Prove Inequality Challenge?"

There is no one specific method or strategy to solve the "Prove Inequality Challenge." It requires a combination of understanding inequalities, critical thinking, and mathematical skills. However, some common approaches include using algebraic manipulations, substitution, and proof by contradiction.

4. Can I use any mathematical tools or software to solve the "Prove Inequality Challenge?"

No, the "Prove Inequality Challenge" is meant to be solved using only your mathematical knowledge and skills. You should not use any tools or software to solve the problem as it defeats the purpose of the challenge.

5. Are there any tips or tricks to make solving the "Prove Inequality Challenge" easier?

The best way to make solving the "Prove Inequality Challenge" easier is to practice solving different types of mathematical inequalities. This will help you develop a better understanding of the concepts and improve your problem-solving skills. Additionally, always double-check your work and try approaching the problem from different angles to ensure your solution is correct.

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