ta có:A=[tex]\sqrt{(\sqrt{x-2}-1)^{2}}+\sqrt{(\sqrt{x-2}-3)^{2}}[/tex]
=[tex]\left | \sqrt{x-2}-1 \right |+\left | \sqrt{x-2}-3 \right |
Áp dụng bđt[tex]\left | a \right |+\left | b \right |\geq \left | a+b \right |[/tex], ta có
[[tex]\left | \sqrt{x-2}-1 \right |+\left | \sqrt{x-2}-3 \right |\geq \left | \sqrt{x-2}-1+3-\sqrt{x-2} \right | =2[/tex]
dấu = xảy ra khi x=3
nhớ like cho mình