Using it's concept, an even function is given by:
B. [tex]F(x) = 2\cos{\frac{1}{2}x}[/tex]
What are even functions?
Even functions are functions for which the following statement is true for all values of x.
f(x) = f(-x).
The cosine function, without a phase shift, is an example of an even function, hence option B is correct.
More can be learned about even functions at https://brainly.com/question/3964641
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