Question

TÌM GIÁ TRỊ LỚN NHẤT, NHỎ NHẤT 

Answer 1

\(B=\dfrac{2x^2+2x+2}{2\left(x^2+1\right)}=\dfrac{x^2+1+x^2+2x+1}{2\left(x^2+1\right)}=\dfrac{1}{2}+\dfrac{\left(x+1\right)^2}{2\left(x^2+1\right)}\ge\dfrac{1}{2}\)

\(B=\dfrac{2x^2+2x+2}{2\left(x^2+1\right)}=\dfrac{3\left(x^2+1\right)-x^2+2x-1}{2\left(x^2+1\right)}=\dfrac{3}{2}-\dfrac{\left(x-1\right)^2}{2\left(x^2+1\right)}\le\dfrac{3}{2}\)