6. A square has four rotational symmetries (0, 90, 180, and 270), and four mirror symmetries. These eight symmetries constitute a group under the binary operation of performing one transformation after the other; this group is sometimes called D4. 0 Find two elements (1,!) in D4 so that a *b = 6* a. 0 Find two elements a, b in D4 so that a *b 75 6* a