Đk x \(\ge0\)
P = \(\dfrac{2\left(\sqrt{x}+1\right)-3}{\sqrt{x}+1}\) = 2 - \(\dfrac{3}{\sqrt{x}+1}\)
Để Pmi n <=> 2 - \(\dfrac{3}{\sqrt{x}+1}\) min <=> \(\dfrac{3}{\sqrt{x}+1}\) max <=> \(\sqrt{x}+1\) min
=> \(\sqrt{x}+1\) = 1
<=> x = 0
x = 0 => Pmin = -1
Vậy Pmin = -1 <=> x = 0