Problem 1(6+6+6+6 points ) Prove or disprove: For each of the following, if it is true, then provide a proof, otherwise provide a counterexample and justify why the counterexample works. (a) If f=O(g) then g=O(f). (b) If f=(h) and g=(h), then f+g=(h). (c) If f=O(g) and g=O(h) then f=O(h). (d) If f=(g) and h=(g) then f=(h)