Find the trigonometric form of the complex number shown below.
$8 i$
A) $8 ( \cos \pi + i \sin \pi )$
B) $8 \left( \cos \frac { \pi } { 2 } + i \sin \frac { \pi } { 2 } \right)$
C) $8 \left( \cos \frac { 3 \pi } { 2 } + i \sin \frac { 3 \pi } { 2 } \right)$
D) $8 \left( \cos \frac { \pi } { 4 } + i \sin \frac { \pi } { 4 } \right)$
E) $8 ( \cos 0 + i \sin 0 )$

Question

Quizplus · Accepted Answer

The trigonometric form of a complex number is $r(\cos \theta + i\sin \theta)$, where $r$ is the magnitude of the complex number and $\theta$ is the argument. For $8i$, $r = 8$ and $\theta = \frac{\pi}{2}$, because the complex number lies on the positive imaginary axis.

Find the Trigonometric Form of the Complex Number Shown Below 8i8 i8i

Find the Trigonometric Form of the Complex Number Shown Below $8 i$