a) \(\sqrt{\left(x-2\right)^2}\) vì x ≥2 b) \(\sqrt{x^2}\) vì x<0
⇒x-2 ≥0 ⇒\(\left(\sqrt{x^2}\right)^2=x^2\)
⇒\(\sqrt{\left(x-2\right)^2}=x-2\) ⇒\(\sqrt{x^2}=x\)
c)\(\sqrt{\left(x+1\right)^2}=x+1\)
⇒\(\left(\sqrt{\left(x+1\right)^2}\right)^2=\left(x+1\right)^2\)
⇒\(\sqrt{\left(x+1\right)^2}=x+1\)