Stuck on this one problem

Express the complex number in trigonometric form.

-5i

5(cos 270° + i sin 270°)

5(cos 180° + i sin 180°)

5(cos 90° + i sin 90°)

5(cos 0° + i sin 0°)

Question

Stuck on this one problem

Express the complex number in trigonometric form. 

-5i

5(cos 270° + i sin 270°)

 5(cos 180° + i sin 180°)

 5(cos 90° + i sin 90°)

 5(cos 0° + i sin 0°)

anonymous · Answer

the absolute value is pretty clearly 5, ad that is in each of your answer
the only question is, what is the angle?

anonymous · Answer

How would i figure out the angle?

anonymous · Answer

|dw:1401675457340:dw|

anonymous · Answer

|dw:1401675483127:dw|

anonymous · Answer

still pretty confused
sorry :(

anonymous · Answer

oh wait! would it be 3pi/5 which would mean the angle is 270 degrees?

anonymous · Answer

@satellite73

anonymous · Answer

it is $\frac{3\pi}{2}$ i think is what you mean

anonymous · Answer

and yes, $270$

anonymous · Answer

yea i meants 3pi/2 not 5 haha, but thanks so much!

anonymous · Answer

you see it with your eyeballs 
yw