Show that if x and y are real numbers then 2xy<or= x^2 + y^2. Please show steps.?

Answer 1

(x - y)^2 >= 0
x^2 -2xy + y^2 >= 0
x^2 + y^2 >= 2xy

Answer 2

Since x,y are real ##, (x-y)^2 must be zero or+ve ( Cannot be -ve).
(x^2+y^2)-2xy>=0
meaning that 2xy must be less than or equal to the 1st term.

Answer 3

It seems to me that you are either struggling with math this year, or not doing your homework.

Let your teacher know that you aren't grasping it and get some help early. It can be a very frustrating subject.

I do not know the answer either, so don't feel bad.

Answer 4

last time i checked, "X" and "Y" were not numbers at all. They were in fact "letters" which means they belong in spelling and not math. Thus, for proof you can find them both in any dictionary.