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

  • Level: Graduate 
  • Thread starter Thread starter bill01
  • Start date Start date
  • Tags Tags
    Inequality
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
3 replies · 2K views
bill01
Is it possible to prove this:
x^x + y^y < (x+y)^(x+y) for every x,y >=1 ?
 
Mathematics news on Phys.org
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.
 
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.
 
  • Like
Likes   Reactions: RaulTheUCSCSlug
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.
 
Last edited by a moderator: