MATH

Another question...
Which of the following expressions is a sixth root of unity?

1. i
2. -1
3. -i
4. All of the above are correct

I appreciate the help.

1. 👍 0
2. 👎 0
3. 👁 733
1. e^0 i = cos 0 + i sin 0 = 1 that does not help much

e^2 pi i = cos 2pi + i sin 2pi = 1

so
1^(1/6) e^(2 pi/6)i
2 pi/6 = pi/3 = 60 deg
so cos theta + i sin theta
0 deg 1
60 deg
120 deg
180 deg -1
240 deg
300 deg
none of these is along the i axis so i and -i are out
only 2. which is -1 at 180 degrees is in

1. 👍 0
2. 👎 0
posted by Damon
2. thank you so much!!!

1. 👍 0
2. 👎 0
posted by Hali
3. You are welcome :)

1. 👍 0
2. 👎 0
posted by Damon

Similar Questions

1. precalc

express the roots of unity in standard form a+bi. 1.) cube roots of unity 2.) fourth roots of unity 3.) sixth roots of unity 4.) square roots of unity

asked by Yoshi on April 20, 2011
2. precalculus

express the roots of unity in standard form a+bi. 1.) cube roots of unity 2.) fourth roots of unity 3.) sixth roots of unity 4.) square roots of unity

asked by Yoshi on April 20, 2011
3. College Algebra

I need some help with a handful of questions. I need to see the steps on how to get to the final answers. I would also appreciate if you can explain how you got to those steps. Rationalize each expression by building perfect nth

asked by Krissy on January 21, 2013
4. College Algebra

I need some help with a handful of questions. I need to see the steps on how to get to the final answers. I would also appreciate if you can explain how you got to those steps. Rationalize each expression by building perfect nth

asked by Krissy on January 19, 2013

I need some help with a handful of questions. I need to see the steps on how to get to the final answers. I would also appreciate if you can explain how you got to those steps. Rationalize each expression by building perfect nth

asked by Krissy on January 20, 2013
6. Math

Rationalize the denominator. Assume that all expressions under radicals represent positive numbers. The square root of 3y^4 to the third root divided by the square root of 15x^4 to the third root. Here is what I have so far: I

asked by B.B. on May 21, 2010
7. Math

Simplify by taking roots of the numerator and the demoninator. Assume that all expressions under radicals represent positive numbers. The square root of 243x^6/y^20 to the fifth root. Here is what I have so far: the square root of

asked by B.B. on May 21, 2010
8. math

Solve for x: [Sixth root of 27]+[cube root of x] = 6/(3-[square root of 3]

asked by Sidney on February 14, 2011