Since g(x) = 2cos(x) and the range of the cosine function is
[-1, 1], the range of g is [-2, 2]. Consequently, the graph
of g is the blue graph. Since f(0) = 0 the graph of f is the
red graph. and, by the process of elimination, the graph of f + g is the
brown graph.
Note. This comment only applies to the original
functions on this page and not necessarily to any changes which you make.