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Grade 12th PassDiscuss with colleagues and IITians

If x,y,z are any three positive numbers, then show that

x^2/y + y^2/z + z^2/x >= x+y+z.

Profile image of Speed Racer
14 Years agoGrade 12th Pass
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2 Answers

Profile image of Ashwin Muralidharan IIT Madras
ApprovedApproved Tutor Answer14 Years ago

Hi Speed Racer,

 

Consider,

x2/y + y, and apply AM-GM inequality:

You will get

x2/y + y ≥ 2x

Apply this cyclically, and add, you will get (x2/y+y)+(y2/z+z)+(z2/x+x)≥2(x+y+z)

And hence the given inequality: (x2/y)+(y2/z)+(z2/x)≥(x+y+z).

 

Hope that helps.

 

All the best.

Regards,

Ashwin (IIT Madras).

Profile image of basit ali
14 Years ago

LHS=X2/y+y2/z+z2/x

     =x3z+y3x+z3y/ xyz     ( suppose put min. value of x,y,z i.e= 0)

    then it is ∞ and when putiing any other value of those i.e. 1 then it becomes 3 i.e  equal to RHS.

                                or

   put the AM- GM inequality then it also clear this statement.!!!

       if u like it plz approve it!!!!