Answer:
9√15·cis(19π/24)
Step-by-step explanation:
The magnitudes multiply and the angles add:
= ((3√3)(3√5))·cis(π/8 +2π/3)
= 9√15·cis(π(1/8 +2/3)) = 9√15·cis(π(3/24 +16/24))
= 9√15·cis(19π/24)
