If f of x is an even function, which statement about the graph of f of x must be true?

An even function satisfies f(-x) = f(x) for every x in its domain. This means that whenever (x, f(x)) is on the graph, (-x, f(x)) is also on it, so the graph is mirrored across the y-axis. Therefore, the statement that must be true is that it has line symmetry about the y-axis.

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