Ta có : \(\sqrt{x}\ge0\forall x\)
\(\Rightarrow\frac{1}{3}+\sqrt{x}\ge0+\frac{1}{3}\)
\(\Rightarrow\frac{1}{3}+\sqrt{x}\ge\frac{1}{3}\)
=> GTNN là 1/3.
Ta có : \(2\sqrt{x+2}\ge0\forall x\)
\(\Rightarrow5-2\sqrt{x+2}\ge5-0\)
\(\Rightarrow5-2\sqrt{x+2}\ge5\)
=> GTLN là 5 .