\(x^4+x^2+2=\) \(\left(x^2\right)^2+2.x^2.\frac{1}{2}+\frac{1}{4}-\frac{1}{4}+2\)
\(=\left(x^2+\frac{1}{2}\right)^2+\frac{7}{4}>0\)với mọi x
\(\left(x+3\right)\left(x-11\right)+2014=\) \(x^2-11x+3x-33+2014\)
\(=\) \(x^2-8x+1981\)
\(=\) \(x^2-2.x.4+16+1965\)
\(=\) \(\left(x-4\right)^2+1965>0\)với mọi x