Graph |z| > 3 on the Complex Plane: A Detailed Explanation

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In summary, To graph |z| > 3 on the complex plane, draw a circle with a radius of 3 and shade the outside.
  • #1
Raerin
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I have no idea where to post this.

How to graph |z| > 3 on the complex plane? A detailed explanation of how the graph shall look like would be very nice :D

Thanks!
 
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  • #2
Hello,
|z| means length of z from origin, so the length of the circle is greater Then 3
Regards,
\(\displaystyle |\pi\rangle\)
 
  • #3
I understand that, but I have no idea how the graph should look like. I don't know how to draw it to illustrate that the radius is greater than 3.
 
  • #4
Raerin said:
I understand that, but I have no idea how the graph should look like. I don't know how to draw it to illustrate that the radius is greater than 3.
I think the simplest way to graph this is to draw the circle |z| = 3, then shade the outside of the circle. It's not perfect, but it gets the idea across.

-Dan
 
  • #5


I would be happy to provide a detailed explanation on how to graph |z| > 3 on the complex plane. First, let's define what |z| means. In the complex plane, z represents a complex number, which has a real part (a) and an imaginary part (bi). The absolute value or modulus of a complex number is denoted by |z| and is defined as the distance from the origin (0+0i) to the point representing the complex number. This can be calculated using the Pythagorean theorem as |z| = √(a^2+b^2).

Now, let's focus on the inequality |z| > 3. This means that the distance from the origin to the point representing the complex number z is greater than 3. To graph this on the complex plane, we will use the Cartesian coordinate system where the horizontal axis represents the real numbers and the vertical axis represents the imaginary numbers.

To begin, draw the x and y axes intersecting at the origin. The point (3,0) on the x-axis represents a complex number with a real part of 3 and an imaginary part of 0. Similarly, the point (0,3) on the y-axis represents a complex number with a real part of 0 and an imaginary part of 3. These two points form a square with the origin as its center.

Next, we need to shade the region outside of this square to represent the points that satisfy the inequality |z| > 3. This is because all the points outside of the square have a distance greater than 3 from the origin.

To further visualize this, we can also plot a few points on the graph. For example, the point (4,2) represents a complex number with a distance of √(4^2+2^2) = √20 > 3 from the origin. Similarly, the point (-2,-2) represents a complex number with a distance of √((-2)^2+(-2)^2) = √8 > 3 from the origin.

Overall, the graph of |z| > 3 on the complex plane will look like a shaded region outside of a square centered at the origin. I hope this explanation helps you understand how to graph this inequality on the complex plane.
 

1. What is the complex plane?

The complex plane, also known as the Argand plane, is a mathematical representation of complex numbers using a horizontal real axis and a vertical imaginary axis. It allows us to visualize and perform operations on complex numbers.

2. What does |z| mean in this context?

The vertical bars around z, also known as the modulus or absolute value, represent the distance of the complex number z from the origin on the complex plane. It is calculated as the square root of the sum of the squares of the real and imaginary parts of z.

3. Why is the inequality |z| > 3 represented on the complex plane?

Representing an inequality on the complex plane allows us to visualize and understand the set of complex numbers that satisfy the inequality. In this case, the inequality |z| > 3 represents all complex numbers whose distance from the origin is greater than 3, forming a circle on the complex plane.

4. How can we determine the set of complex numbers that satisfy the inequality?

To determine the set of complex numbers that satisfy the inequality, we can plot the complex numbers on the complex plane and see which numbers fall outside the circle with a radius of 3 centered at the origin. Alternatively, we can square both sides of the inequality and solve for the real and imaginary parts of z to find the range of values that satisfy the inequality.

5. What are some practical applications of representing inequalities on the complex plane?

Representing inequalities on the complex plane is useful in many fields, including physics, engineering, and economics. It allows us to analyze and visualize complex systems and make predictions based on mathematical models. In particular, representing complex numbers in polar form on the complex plane is useful in analyzing periodic phenomena and performing operations such as multiplication and division.

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