What is the product of 4 left-bracket cosine (StartFraction 2 pi Over 3 EndFraction) + I sine (StartFraction 2 pi Over 3 EndFrac
tion) right-bracket and 2 left-bracket cosine (StartFraction pi Over 3 EndFraction) + I sine (StartFraction pi Over 3 EndFraction right-bracket? Answer its D im just adding this for others to find