Question

Answer 1

a: ĐKXĐ: x>=0; x<>1

b: \(Q=\frac{1}{1-\sqrt{x}}+\frac{1}{\sqrt{x}}\)

\(=\frac{\sqrt{x}+1-\sqrt{x}}{\sqrt{x}\left(1-\sqrt{x}\right)}=\frac{1}{\sqrt{x}\left(1-\sqrt{x}\right)}\)

c: TH1: 0<x<1

=>\(\sqrt{x}<1\)

=>\(\sqrt{x}-1<0\)

=>\(1-\sqrt{x}>0\)

=>\(\sqrt{x}\left(1-\sqrt{x}\right)>0\)

=>\(Q=\frac{1}{\sqrt{x}\left(1-\sqrt{x}\right)}>0\)

TH2: x>1

=>\(\sqrt{x}>1\)

=>\(\sqrt{x}-1>0\)

=>\(1-\sqrt{x}<0\)

=>\(\sqrt{x}\left(1-\sqrt{x}\right)<0\)

=>\(Q=\frac{1}{\sqrt{x}\left(1-\sqrt{x}\right)}<0\)