Question

Change to trigonometric form; then find the indicated power. Leave your result in trigonometric form: r(cos theta+i sin theta).

-1 - i in trigonometric form =
a. 2(cos225+isin225)
b. 2(cos135+isin135)
c. sqrt2(cos225+isin225)
d. sqrt2(cos135+isin135)

Answer 1

use these formulas
for any complex number : a+bi
\[r = \sqrt{a^{2}+b^{2}}\]
\[\tan \theta = \frac{b}{a}\]

Answer 2

also you need to identify which quadrant you are in to get the right angle
imagine you are plotting the point (a,b)

Answer 3

hope i didn't lose you...do you understand the formula and what (a,b) refer to for this problem

Answer 4

Oh, sorry, bad connection :/ But yea, so r=1.414?

Answer 5

yes,right...which is sqrt 2

Answer 6

So now... ?

Answer 7

now u find tan theta=b/a..and hence find theta

Answer 8

I think I got it. C.?

Answer 9

yes C it is :)

Answer 10

Thank you!