Question

Prove that (x + y)^2 >= 4xy

Answer 1

\[\large\hspace{11pt}(x+y)^2-4xy\\=x^2+2xy+y^2-4xy\\=x^2-2xy+y^2\\=(x-y)^2\\\ge0\\\because(x+y)^2-4xy\ge0\\\therefore(x+y)^2\ge4xy\]

Answer 2

Thanks!

Answer 3

no problem :)

Answer 4

I love your face :D

Answer 5

Nice smile, isn't it? :D

Answer 6

yep xD

Answer 7

have a great great great day :D
bye :D

Answer 8

Have a good one yourself! :D