Question

chứng minh :\(\sqrt{A}+\sqrt{B}=0\Leftrightarrow\left\{{}\begin{matrix}A=0\\B=0\end{matrix}\right.\)

Answer 1

; \(\sqrt{B}\ge0\) Mà \(\sqrt{A}+\sqrt{B}=0\) => \(A=0;B=0\)

Answer 2

Ta có \(\sqrt{A}\ge0,\sqrt{B}\ge0\Rightarrow\sqrt{A}+\sqrt{B}\ge0\)

Vậy muốn xảy ra dấu '=' thì \(\sqrt{A}=\sqrt{B}=0\Leftrightarrow A=B=0\)(đpcm)