How do you write the complex number in trigonometric form $-5i$ ?

Question

5154 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-02-26T08:10:55

The answer is $=5(cos(-1/2pi)+isin (-1/2pi))$

The trigonometric form of a complex number is

$z=r(costheta+isin theta)$

Here, we have

$z=-5i$

Therefore,

$r=5$

$costheta=0$

$sin theta=-1$

So, $theta=-1/2pi$

$z=5(cos(-1/2pi)+isin (-1/2pi))$

$=5e^(-1/2ipi)$

How do you write the complex number in trigonometric form -5i-5i?