Question

Express the complex number in trigonometric form.
-2i


2(cos 180° + i sin 180°)

2(cos 90° + i sin 90°)

2(cos 270° + i sin 270°)

2(cos 0° + i sin 0°)

Answer 1

Put it in the complex plane and look up |-2i| and the argument

Answer 2

I have no idea what you're talking about.

Answer 3

So the first choice..?