We have
$(x-y)^2 >=0$ or $x^2 + y^2 >=2xy$
$(x-1)^2 >=0$ or $x^2 + 1 >= 2x$
$(y-3)^2 >= 0$ or $y^2 + 9 >= 6y$
Adding we get $2(x^2+y^2 + 5) >= 2(xy+x + 3y)$
Or $x^2+y^2 + 5 >= xy + x + 3y$
This is equal when x = y, y = 3, x= 1 which canot be true so $x^2+y^2 + 5 > xy + x + 3y$
No comments:
Post a Comment