Question 26: Let the function y = f (x) be determined, continuous on \(\mathbb{R}\) and have a graph as shown below. Find the number of extreme points of the function y =|f(|x|)|

Step 1: Graph the function y=f(|x|):

+ Keep the graph of the function f(x) to the right of the Oy cylinder. remove the part of the graph f(x) to the left of the Oy axis.

+ Symmetric the part of the graph f(x) to the right of the Oy axis through Oy

Step 2: Graph the function y =|f(|x|)|

+ Keep the part of the graph f(x) above the Ox axis. Symmetry the part of the graph that lies below the Ox axis through Ox

+ Remove the part of the graph below the Ox . axis

Based on the graph of the function y=|f(|x|)| deduce the function has 11 extreme points

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