Question

Express the complex number in trigonometric form.

2i
Answer choices:
(a)2(cos 180° + i sin 180°)
(b)2(cos 0° + i sin 0°)
(c)2(cos 270° + i sin 270°)
(d)2(cos 90° + i sin 90°)

Answer 1

2i=2(0+1i)=2(cos \(\theta+i\sin \theta\))
now you can find \( \theta\)

Answer 2

\[\cos \theta=0,\theta=90,270\]
\[\sin \theta=1,\theta=90\]
\[\theta=?\]