Question

tìm Min

A=(x+y)^2 + (x+1)^2+(y-2)^2

Answer 1

\(A=\left(x+y\right)^2+\left(x+1\right)^2+\left(y-2\right)^2\)

Có \(\left\{{}\begin{matrix}\left(x+y\right)^2\ge0\forall x,y\\\left(x+1\right)^2\ge0\forall x\\\left(y-2\right)^2\ge0\forall y\end{matrix}\right.\)

Suy ra : \(\left\{{}\begin{matrix}x+y=0\\x+1=0\\y-2=0\end{matrix}\right.=>\left\{{}\begin{matrix}x=y\\x=-1\\y=2\end{matrix}\right.\)

Cái bài này mình ko chắc nha ^^ . Mk thấy nó ko hợp lí.