\(E=\left(x+\frac{3}{2}\right)^2-\frac{5}{4}\ge-\frac{5}{4}\Rightarrow E_{min}=-\frac{5}{4}\) khi \(x=-\frac{3}{2}\)
\(F=\left(x^2+5x+4\right)\left(x^2+5x+6\right)=\left(x^2+5x+4\right)+2\left(x^2+5x+4\right)+1-1\)
\(F=\left(x^2+5x+5\right)^2-1\ge-1\)
\(\Rightarrow E_{min}=-1\) khi \(x^2+5x+5=0\Rightarrow x=\frac{-5\pm\sqrt{5}}{2}\)
\(M=\frac{2}{-4-\left(3x-1\right)^2}\ge\frac{2}{-4}=-\frac{1}{2}\Rightarrow M_{min}=-\frac{1}{2}\) khi \(x=\frac{1}{3}\)
\(P=\frac{x^2+2x+3}{x^2+2}\Rightarrow Px^2+2P=x^2+2x+3\)
\(\Rightarrow\left(P-1\right)x^2-2x+2P-3=0\)
\(\Delta'=1-\left(P-1\right)\left(2P-3\right)\ge0\)
\(\Leftrightarrow-2P^2+5P-2\ge0\Rightarrow\frac{1}{2}\le P\le2\)
\(\Rightarrow P_{max}=2\) khi \(x=1\)
\(P_{min}=\frac{1}{2}\) khi \(x=-2\)
