QCEVault

Complex numbers — Question 11

Original QCE Vault practice · 1 mark

Q11 · Practice questionSimple familiar1 mark

QUESTION 11

Let z1=2cis⁡(π/3)z_1=2\operatorname{cis}(\pi/3) and z2=3cis⁡(−π/6)z_2=3\operatorname{cis}(-\pi/6). The product z1z2z_1z_2 is
(A)
6cis⁡(π/2)6\operatorname{cis}(\pi/2)
(B)
5cis⁡(π/6)5\operatorname{cis}(\pi/6)
(C)
6cis⁡(π/6)6\operatorname{cis}(\pi/6)
(D)
6cis⁡(−π/2)6\operatorname{cis}(-\pi/2)
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