## Itel Group Title Express the complex number in trigonometric form. -4 one year ago one year ago

1. frx Group Title

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

2. frx Group Title

Try to think of the unitcircle

3. frx Group Title

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

4. Itel Group Title

180 degrees?

5. Itel Group Title

@frx

6. frx Group Title

Exactly

7. frx Group Title

Or pi since you're looking for the polarform

8. Itel Group Title

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. frx Group Title

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

10. frx Group Title

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

11. frx Group Title

So it's the last one of your options

12. Itel Group Title

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

13. frx Group Title

No problem :)

14. frx Group Title

If you have any questions just send a pm