Perform the operation shown below and leave the result in trigonometric form.

Question

[6(cos 5pi/6 + isin 5pi/6)] [3(cos 4pi/5 + isin 4pi/5)]

Answer 1

6cis 5π/6 * 3cis 4π/5
= 6*3 cos(5π/6 + 4π/5)
= 18 cis 49π/30