a.\(-\sqrt{x+1}\le0\)
Dấu "=" xảy ra \(\Leftrightarrow x=-1\)
\(\Rightarrow A=-\sqrt{x+1}+5\le5\)
Dấu "=" xảy ra \(\Leftrightarrow x=-1\)
Vậy \(A_{max}=5\Leftrightarrow x=-1\)
b.\(-\sqrt{x-1}\ge0\)
Dấu "=" xảy ra \(\Leftrightarrow x=1\)
\(\Rightarrow A=\sqrt{x+1}+5\ge2\)
Dấu "=" xảy ra \(\Leftrightarrow x=1\)
Vậy \(B_{min}=2\Leftrightarrow x=1\)
a) ĐK: \(x\ge-1\)
Có \(-\sqrt{x+1}\le0\forall x\ge-1\)
\(\Rightarrow A\le5\) \(\Rightarrow max_A=5\)
dấu "=" xảy ra \(\Leftrightarrow-\sqrt{x+1}=0\Leftrightarrow x=-1\)
b) ĐK: \(x\ge1\)
Ta có \(\sqrt{x-1}\ge0\forall x\ge1\)
\(\Rightarrow B\ge2\Rightarrow min_B=2\)
dấu "=" xảy ra <=> x=1