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For how many integers $x$ is the number $x^{4}-7x^{2}+10$ negative? (  2014 AMC 10B Problems, Question \#20) 
Overseas Competition->Knowledge Point->Calculation Modules
Factor the polynomial as $\left(x^{2}-5\right)\left(x^{2}-2\right)$. Since this expression is negative, one term must be negative and the other positive. Also, the first term is obviously smaller than the second, so $x^{2}-5\textless0\textless x^{2}-2$. Solving this inequality, we find $2\textless x^{2}\textless5$. There are exactly $2$ integers $x$ that satisfy this inequality, $\pm 2$. Thus our answer is $(\mathbf{A}) 2$. 