Question

giải pt

\(\sqrt{x^2}=x\)

\(\sqrt{x^2-4x+4}=x-2\)

Answer 1

a: Ta có: \(\sqrt{x^2}=x\)

\(\Leftrightarrow\left|x\right|=x\)

hay \(x\ge0\)

b: Ta có: \(\sqrt{x^2-4x+4}=x-2\)

\(\Leftrightarrow\left|x-2\right|=x-2\)

\(\Leftrightarrow x\ge2\)

Answer 2

\(\sqrt{x^2}=x\Leftrightarrow\left|x\right|=x\Leftrightarrow x\ge0\)

\(\sqrt{x^2-4x+4}=x-2\left(x\in R\right)\\ \Leftrightarrow\left|x-2\right|=x-2\\ \Leftrightarrow x-2\ge0\Leftrightarrow x\ge2\)