Question

Multiply.


`(√(2))/(6)cis ((3\pi )/(5))`·
`(√(6))/(4)cis ((2\pi )/(3))`

A.
`(√(3))/(12)cis((19\pi )/(15))`
B.
`(√(3))/(12)cis((2\pi )/(5))`
C.
`(√(2))/(8)cis((2\pi )/(5))`
D.
`(√(2))/(8)cis((19\pi )/(15))`

Answer 1

Multiply the moduli and add the arguments:

√2/6 cis(3π/5) × √6/4 cis(2π/3)

= (√2/6 × √6/4) cis(3π/5 + 2π/3)

= √3/12 cis(19π/15) … [A]