Problem 4 [20 points]. Find the Maclaurin series for f and its radius of convergence. You may use either the direct method (definition of a Maclaurin series) or a known series. f (x) = cos(Problem 7 [20 points]. Plot the r - 0 graph (i.e. the graph that shows r as a function against 0), complete the table and sketch the polar curve r = cos(30), where 0