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Since connectedness components are always both open and close sets, you need an example in which "connected" is not the same as "path connected". Let A be the line segment, in, from (-1, 0) to (0,0) inclusive (so it is a closed set). Let B be the graph of y= sin(1/x) for
. Let the topological space, X, be
. A and B are "path components" of X but B is neither open nor closed.