A function f (x) is symmetric with respect to the vertical line x = a if f

Question:

A function f (x) is symmetric with respect to the vertical line x = a if f (a − x) = f (a + x).
(a) Draw the graph of a function that is symmetric with respect to x = 2.
(b) Show that if f (x) is symmetric with respect to x = a, then g(x) = f (x + a) is even.