Question

Express the complex number in trigonometric form.

-6i

Answer 1

to convert it to trigonometric form, you need to find r and \(\theta\)

bring 6i in the form of x+iy

then
\(r = \sqrt{x^2+y^2}\)
and
\(\theta = \arctan(y/x)\)

Answer 2

then your trigonometric form will be
\(r (\cos \theta + i \sin \theta)\)

Answer 3

**
-6i

Answer 4

6(cos 90 + i sin 90)?

Answer 5

sure?

Answer 6

lets verify

6 cos 90 = 6*0 = 0

6 sin 90 = 6

so its actually +6i
but we need -6i

Answer 7

oh!!! 6(cos 180 + i sin 180)

Answer 8

not actually...
cos 180 is not 0..


we just need a negative sign in between,

so we can take the angle as -90

and whats the positive angle representation of -90 ???

hint: add 360

Answer 9

270...

Answer 10

yep