# How do you express the complex number in trigonometric form 2i?

May 22, 2016

#### Answer:

I found: $z = 2 \left(\cos \left(\frac{\pi}{2}\right) + i \sin \left(\frac{\pi}{2}\right)\right)$

#### Explanation:

If you plot this complex number on the complex plane you'll see it as:

It has a modulus (length) of $2$ and argument (angle with positive Re semiaxis) of $\frac{\pi}{2}$.
So in trigonometric form your number will be:
$z = 2 i = 2 \left(\cos \left(\frac{\pi}{2}\right) + i \sin \left(\frac{\pi}{2}\right)\right)$