What is 3 [cos (60o ) i sin 60o] • One-half [cos (15o) i sin (15o)]? Three-halves left-bracket cosine (75 degrees) I sine (75 degrees) right-bracket 3 and one-half left-bracket cosine (75 degrees) I sine (75 degrees) right-bracket 3 and one-half left-bracket cosine (45 degrees) I sine (45 degrees) right-bracket Three-halves left-bracket cosine (45 degrees) I sine (45 degrees) right-bracket