Plotting the roots of unity on the complex plane

In summary, the conversation discusses finding the 6th complex roots of √3 + i and plotting these roots on the complex plane. The roots are found by using the equation z^6=2(cos(π/6)+isin(π/6)) and the values of z are determined for different values of k. The roots are evenly distributed around the circle, with each one being rotated by π/3 from the next.
  • #1
Cottontails
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Homework Statement


Find the 6th complex roots of √3 + i.

Homework Equations


z^6=2(cos(π/6)+isin(π/6))
r^6=2, r=2^1/6
6θ=π/6+2kπ, θ=π/36+kπ/3

The Attempt at a Solution


When k=0, z = 2^1/6(cos(π/36)+isin(π/36)),
When k=1, z = 2^1/6(cos(13π/36)+isin(13π/36)),
When k=2, z = 2^1/6(cos(25π/36)+isin(25π/36)),
When k=3, z = 2^1/6(cos(37π/36)+isin(37π/36)),
When k=4, z = 2^1/6(cos(49π/36)+isin(49π/36)),
When k=5, z = 2^1/6(cos(61π/36)+isin(61π/36)).
I just want help with plotting these roots on the complex plane. So, I am just wondering, are all roots of unity on the complex plane the same, regardless of the equation? By this, I mean, are the position of the roots the same, regardless of what the equation is?
 
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  • #2
Cottontails said:

Homework Statement


Find the 6th complex roots of √3 + i.

Homework Equations


z^6=2(cos(π/6)+isin(π/6))
r^6=2, r=2^1/6
6θ=π/6+2kπ, θ=π/36+kπ/3

The Attempt at a Solution


When k=0, z = 2^1/6(cos(π/36)+isin(π/36)),
When k=1, z = 2^1/6(cos(13π/36)+isin(13π/36)),
When k=2, z = 2^1/6(cos(25π/36)+isin(25π/36)),
When k=3, z = 2^1/6(cos(37π/36)+isin(37π/36)),
When k=4, z = 2^1/6(cos(49π/36)+isin(49π/36)),
When k=5, z = 2^1/6(cos(61π/36)+isin(61π/36)).
I just want help with plotting these roots on the complex plane. So, I am just wondering, are all roots of unity on the complex plane the same, regardless of the equation? By this, I mean, are the position of the roots the same, regardless of what the equation is?

These aren't the roots of unity. They are the roots of ##\sqrt 3 +i##. I'm not sure what you mean by the position being the same. What they are is distributed evenly around the circle. In this example, each one is rotated ##\frac \pi 3## from the next, so by the time you do that 6 times, you are all the way around.
 

FAQ: Plotting the roots of unity on the complex plane

What are the roots of unity?

The roots of unity are the solutions to the equation x^n = 1, where n is a positive integer. In other words, they are the numbers that, when raised to the nth power, equal 1.

Why are the roots of unity plotted on the complex plane?

The complex plane is a useful tool for visualizing and understanding complex numbers, which are numbers that have both a real and imaginary component. Since the roots of unity are complex numbers, plotting them on the complex plane helps us see their relationships and patterns.

How many roots of unity are there?

There are always n distinct roots of unity for any positive integer n. For example, there are 3 roots of unity when n = 3: 1, -0.5 + 0.866i, and -0.5 - 0.866i.

What is the significance of the roots of unity?

The roots of unity have many important applications in mathematics and science. They are used in fields such as number theory, algebra, and signal processing. They also have connections to trigonometry and geometry, and are often used in complex analysis to solve problems involving complex numbers.

How are the roots of unity calculated and plotted on the complex plane?

To calculate the roots of unity, we use De Moivre's formula, which states that the nth roots of unity can be expressed as (cos(2πk/n) + i sin(2πk/n)), where k is an integer from 0 to n-1. To plot the roots on the complex plane, we simply plot these values as points on the unit circle, with the real part as the x-coordinate and the imaginary part as the y-coordinate.

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