What is the Minimum Value of f(x) for Positive Real Numbers x and y?

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mathlover1
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For all positive real numbers [tex]x,y[/tex] prove that:

[tex]\frac{1}{1+\sqrt{x}}+\frac{1}{1+\sqrt{y}} \geq \frac{2\sqrt{2}}{1+\sqrt{2}}[/tex]
 
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mathlover1 said:
For all positive real numbers [tex]x,y[/tex] prove that:

[tex]\frac{1}{1+\sqrt{x}}+\frac{1}{1+\sqrt{y}} \geq \frac{2\sqrt{2}}{1+\sqrt{2}}[/tex]

No proof is possible.
Let x=y=1, then left hand side is equal to 1 which is strictly less than the right hand side.
 


ohubrismine said:
No proof is possible.
Let x=y=1, then left hand side is equal to 1 which is strictly less than the right hand side.

I forgot to say that x,y are numbers such that x+y=1
 


Since x+y=1, y=1-x. Now, you are looking for the minimum. How would you do it?
 


Tedjn said:
Since x+y=1, y=1-x. Now, you are looking for the minimum. How would you do it?
That's why i am asking to you guys!
This inequality is correct .. just need to be proven!
 


Find the minimum value of
[tex]f(x) = \frac{1}{1 + \sqrt{x} } + \frac{1}{1 + \sqrt{1 - x}}[/tex]

This involves finding the critical points.