Question

√(A).√(A)= √(A.A)= √(A)^2= /A/ hay. =(√A)^2=A ?

Answer 1

\(\sqrt{A}.\sqrt{A}=\sqrt{A.A}=\sqrt{A^2}=\left|A\right|=\left[{}\begin{matrix}A.nếu.A>0\\-A.nếu.A< 0\end{matrix}\right.\)

Answer 2

\(\sqrt{\left(A\right)}.\sqrt{\left(A\right)}=\sqrt{A.A}=\sqrt{A^2}=\left|A\right|\)

Answer 3

`= |A|`.

Answer 4

\(\sqrt{A^2}=\left|A\right|\) nhé vì chưa biết A âm hay không