# Thread: Roots of Complex Numbers

1. ## Roots of Complex Numbers

Can someone please check my work. My instructor said to leave in cis format.

Find the 4th roots of 1+i

2^1/8cis(11.25)
2^1/8cis(25.3)
2^1/8cis(47.81)
2^1/8cis(70.31)

I feel like I'm on the right track...

Thanks for any help.

2. Originally Posted by repete
Can someone please check my work. My instructor said to leave in cis format.

Find the 4th roots of 1+i
2^1/8cis(11.25)
2^1/8cis(25.3)
2^1/8cis(47.81)
2^1/8cis(70.31)
I feel like I'm on the right track.
The numbers in red are wrong.
It would be better to use nunbers or degrees.

3. Ahh ok. It was an arithmetic error. Is this correct?

2^1/8cis(11.25)
2^1/8cis(101.25)
2^1/8cis(191.25)
2^1/8cis(281.25)

Thanks that makes more sense.

4. Originally Posted by repete
Ahh ok. It was an arithmetic error. Is this correct?
2^1/8cis(11.25)
2^1/8cis(101.25)
2^1/8cis(191.25)
2^1/8cis(281.25)
Thanks that makes more sense.
That of course is in degree form.
$\frac{\pi}{16},~\frac{9\pi }{16},~\frac{-7\pi }{16},~\&~\frac{-15\pi }{16}$