Question

What is the product of z1 and z2 if z1 = 2(cos70° + i sin70°) and z2 = 4(cos200° + i sin200°)?

Answer 1

d. 8(cos270* + i sin 270*)

Explanation:

E2020

Answer 2

8(cos270° + i sin270°)

Explanation:

(cos(a) + i * sin(a)) * (cos(b) + i * sin(b)) = cos(a + b) = i * sin(a + b)

2 * 4 * (cos(270) + i * sin(270))

8(cos270° + i sin270°)