Prove AM-GM Inequality: a,b,c ≥ 0 and a+b+c=3

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In summary, the AM-GM inequality is a mathematical principle that states the arithmetic mean is always greater than or equal to the geometric mean for any set of non-negative numbers. It can be proven using various methods, and holds true for any set of non-negative numbers with a finite sum. This inequality has practical applications in mathematics, physics, and engineering, and is often used to prove other theorems and solve optimization problems.
  • #1
klajv
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Can't figure this out and hope to get some help, TIA!

a,b,c >= 0 and a+b+c=3
Prove that a²+b²+c²+ab+bc+ca >= 6
 
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  • #2
Write the left hand side of the inequality differently, using the expression for (a+b+c)^2.

You will arrive upon the inequality ab+bc+ac <= 3 = a+b+c. Now, can you prove ab+bc+ac <= (a+b+c)(a+b+c)/3 ?
 
  • #3
disregardthat <---

Yes, thanks alot
 

1) What is the AM-GM inequality?

The AM-GM inequality, also known as the arithmetic mean-geometric mean inequality, states that for any set of non-negative numbers, the arithmetic mean is always greater than or equal to the geometric mean. In other words, the sum of a set of numbers divided by the number of numbers is always greater than or equal to the nth root of the product of those numbers.

2) How do you prove the AM-GM inequality?

The AM-GM inequality can be proved using various methods, such as the algebraic proof, the geometric proof, or the calculus proof. In this particular case, we can use the algebraic proof which involves expressing the terms in a certain way and then applying the basic properties of arithmetic and inequalities to reach the desired result.

3) What are the conditions for the AM-GM inequality to hold true?

The AM-GM inequality holds true for any set of non-negative numbers. In the given scenario, the conditions are that a, b, and c must be greater than or equal to 0 and their sum must be equal to 3.

4) Can the AM-GM inequality be applied to any set of numbers?

No, the AM-GM inequality can only be applied to non-negative numbers. Additionally, for the inequality to hold true, the number of terms in the set must be finite and the sum of the numbers must be a finite value.

5) What are the practical applications of the AM-GM inequality?

The AM-GM inequality has various applications in mathematics, physics, and engineering. It is often used to prove other mathematical theorems, solve optimization problems, and derive important equations in different fields of science. For example, it is used in economics to find the optimal distribution of a budget among different products.

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