Can the Inequality x^x + y^y < (x+y)^(x+y) be Proven Algebraically?

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In summary, the conversation discusses the possibility of proving the inequality x^x + y^y < (x+y)^(x+y) for all x and y values greater than or equal to 1. The conversation suggests taking the derivative of both equations to compare their change in slope, and also mentions an algebraic solution involving expanding (x+y)^(x+y). The conversation concludes with a preference for an algebraic solution, stating that the equation is not transcendental.
  • #1
bill01
Is it possible to prove this:
x^x + y^y < (x+y)^(x+y) for every x,y >=1 ?
 
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  • #2
Well, let me think, since I am not really sure if this would work for all parameters of x and y... never mind, you have x,y >1! What you could do is take the derivative of both equations to measure it's change in slope, and if (x+y)^(x+y)is greater, then it will have a change in slope that is greater then the other equation. But I am not sure if that is what you want.
 
  • #3
Iam just proving it,just expand the Right side (x+y)^(x+y), u get x multiplied by x+y times which is obviously greater than x^x and same in case of y and remaining terms of expansion are positive as x,y>1 and no negative terms in expansion. hope it helps.
 
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  • #4
Thanks for the answers, but I would prefer an algebraic solution.
I did what Raul said with the graph but I would like an algebraic sol.
I believe that it is solved algebraically and it is not a transcendental equation.
 
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1. Can you explain the concept of proving an inequality?

Proving an inequality means demonstrating that one mathematical expression is greater than, less than, or equal to another expression. This is often done using algebraic manipulations and logical reasoning.

2. How do you know which direction to prove the inequality in?

The direction of the inequality is often indicated by the given problem or by the context of the situation. For example, if the problem asks for the largest possible value of a certain expression, you would need to prove the inequality in the direction of proving the expression is less than or equal to a certain value.

3. What are some common techniques used to prove an inequality?

Some common techniques include algebraic manipulations (such as factoring, expanding, or simplifying expressions), using known properties and theorems (such as the triangle inequality or the AM-GM inequality), and utilizing logical reasoning (such as proving by contradiction or using counterexamples).

4. Is it necessary to prove every step in an inequality proof?

Yes, it is important to show all the steps in an inequality proof to ensure that the logic is clear and correct. Skipping steps or assuming certain steps without showing them can lead to errors in the proof.

5. Are there any tips for successfully proving an inequality?

Some tips include clearly defining the variables and conditions, trying different approaches if you get stuck, and checking your work for errors. It is also helpful to get familiar with common inequality properties and theorems. Practice and patience are key in mastering the skill of proving inequalities.

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