## anonymous 3 years ago Express the complex number in trigonometric form. -4

1. anonymous

So, do you know how to find the the angle?

2. anonymous

Try to think of the unitcircle

3. anonymous

-4 is simply just a scaled-up -1 so that means that the angle is what?

4. anonymous

180 degrees?

5. anonymous

@frx

6. anonymous

Exactly

7. anonymous

Or pi since you're looking for the polarform

8. anonymous

Thanks. These are the possible answers: 4(cos 270° + i sin 270°) 4(cos 90° + i sin 90°) 4(cos 0° + i sin 0°) 4(cos 180° + i sin 180°) So how do I find out which one of those is the answer if it is pi or 180 degrees? thanks again

9. anonymous

$|z|=\sqrt{4^{2}}=4$ $\arg(z)= \pi$ $4(\cos \pi+isin \pi)$

10. anonymous

So since your alternatives are in degrees and not radians you know it's 180 degrees.

11. anonymous

So it's the last one of your options

12. anonymous

Oh i see what you did. Thank you so much man. I really appreciate your help. Very thorough explanation.

13. anonymous

No problem :)

14. anonymous

If you have any questions just send a pm