\(a,A=2x+x^2-2x+2022=x^2+2022\)
b, Thay x=-2 vào A ta có:
\(A=x^2+2022=\left(-2\right)^2+2022=4+2022=2026\)
c, \(A=2023\)
\(\Leftrightarrow x^2+2022=2023\\ \Leftrightarrow x^2=1\\ \Leftrightarrow x=\pm1\)
d, \(A=x^2+2022\ge2022\)
Dấu "=" xảy ra \(\Leftrightarrow x=0\)
Vậy \(A_{min}=2022\Leftrightarrow x=0\)
