Trả lời:
Ta có: \(\left(2x+1\right)^{10}\ge0\forall x\)
\(\Leftrightarrow\left(2x+1\right)^{10}+2\ge2\forall x\)
\(\Leftrightarrow\frac{4}{\left(2x+1\right)^{10}+2}\le\frac{4}{2}\forall x\)
\(\Leftrightarrow-\frac{4}{\left(2x+1\right)^{10}+2}\ge-2\forall x\)
Dấu "=" xảy ra khi 2x + 1 = 0 <=> 2x = -1 <=> x = -1/2
Vậy GTNN của A = - 2 khi x = - 1/2.