(a) Construct the graph of 2cos 3x + 1 in the range 0 ^ 0 <= x <= 120 ^ 0 at intervals of 15 ^ 0
(b) Use your graph to find:
(i) the maximum value of y;
(ii) the minimum value of y;
(iii) the value(s) of x at which
2cos 3x + 1 = 0
