Question 45: Which of the following functions has two maxima and one minimum?

The function \(y = a{x^4} + b{x^2} + c\) (\(a \ne 0\)) has two maxima and one minimum \( \Leftrightarrow \left\ { \begin{array}{l}a < 0\\ab < 0\end{array} \right.\Leftrightarrow \left\{ \begin{array}{l}a < 0\\b > 0\end{ array} \right.\)

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