SOLUTION: How may i prove this using direct proof? Let x,y be real numbers. {{{ x^2+y^2 >= 2xy }}} Please help!! thank you!

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Question 1020219: How may i prove this using direct proof?
Let x,y be real numbers.
+x%5E2%2By%5E2+%3E=+2xy+
Please help!!
thank you!

Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
For all real numbers x, y, it is always true that
%28x-y%29%5E2%3E=0
Expanding the left side of the inequality,
x%5E2+-+2xy+%2By%5E2+%3E=+0
==> x%5E2+%2B+y%5E2+%3E=+2xy after transposition.
And the statement is proved.