Question 29: Given the function \(y = f\left( x \right)\) defined above and have a table considering the sign of the derivative as follows. Then the number of extreme points of the function \(y = f\left( x \right)\) is

Since the function is defined on \(\mathbb{R}\) and has a derivative expression that changes sign three times at \({x_1}; {x_2}; {x_3}\) so the function \(y = f\) left( x \right)\) has three extremes.

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