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Amplitude or Argument of a Complex Number

In this article, we will learn about the complex numbers, definition of argument of complex numbers, its formula, properties and principle and general argument of complex numbers.

The complex plane is an essential component in the study of mathematics. It is also referred to as the z-plane, which is made up of two axes that run in a direction that is perpendicular to each other. Real numbers are represented by the horizontal line, which is often referred to as the real axis. On the other hand, the vertical line is known as an imaginary axis and symbolises numbers that do not exist in reality. A geometric interpretation of complex numbers can be represented on the complex plane. This plane is analogous to the Cartesian plane in that it has the real and imaginary components of a complex number in addition to axes that run in the X and Y directions. There are two different ideas that go hand in hand with complex numbers.

Complex Numbers:

A number is said to be complex if it can be represented in mathematical notation as follows: a + ib, where an is a real number and b is an imaginary number. The complex number contains a symbol I that satisfies the constraint i² = -1, which can be found in the previous sentence. Complex numbers can be thought of as an extension of the one-dimensional number line. Complex numbers are denoted by the symbol. In the complex plane, the point (a, b) is the form in which a complex number that is indicated by the notation a + bi is represented. A complex number that has no real component at all is said to be purely imaginary. Some examples of this type of number include -i, -5i, and other similar expressions. In addition, a complex number is said to be real if there is no imaginary component attached to it.

Argument of complex numbers definition:

The definition of the argument of a complex number is the angle that is formed by tilting the real axis in the direction of the complex number when it is represented on the complex plane. It is represented by the characters “θ” or “φ”. The standard unit for this is called “radians,” and it is used to measure it.

Argument of Complex Numbers formula:

A complex number can be written in polar form as the equation r(cosθ + i sinθ ), which serves as the argument in this particular case. Z represents the complex number, so arg(z) is the notation for the argument function. The complex number can be written as z = x + iy. The following formula can be used to perform the computation needed to analyse the complicated argument:

arg (z) = arg (x+iy) = tan-1(y/x)

As a result, the argument θ can be represented as follows:

Θ = tan-1 (y/x)

Properties of Argument of Complex Numbers:

Let’s take a look at some of the characteristics that are shared by the arguments of complex numbers. If we assume that z is a nonzero complex number and that n is any integer, then we can say that

arg(zn) = n arg(z)

Let us assume that z1 and z2 are two different complex numbers, then

  • arg (z₁/ z₂) = arg ( z₁) – arg ( z₂)
  • arg ( z₁ z₂) = arg ( z₁) + arg ( z₂)

How to find the Argument of Complex Numbers:

  1. Determine which of the given complex number’s components are real and which are imaginary. They will be referred to as x and y, respectively.
  2. Replace the values in the formula Θ = tan-1 (y/x) with the new values.
  3. If the formula does not give any standard value, find the value of tan-1 and write it down in that form. If it does give a standard value, find the value of tan-1.
  4. The required value of the complex argument for the given complex number is this value followed by the unit “radian.”

Principle vs General Argument of Complex Numbers:

An angle formed by the line representation of the complex number with the positive x-axis is used to measure the argument of the complex number. This angle, based on its values, has both a principal value and a general value, which results in the complex number having both a principle argument and a general argument. The trigonometric value of Tan is based on the general solution of the trigonometric tangent function since it is used to determine the argument of the complex number and is therefore used in trigonometric calculations.

Principle Argument Of Complex Number = -π < θ < π

The values that can be assigned to the fundamental argument of complex numbers range from -π < θ < π. In addition, if it is measured counterclockwise with regard to the positive x-axis, the angle is calculated as 0 < θ < π when taken in the first two quadrants of the diagram. In the third and fourth quadrants, with respect to the x-axis that is positive, the angle that is being measured is clockwise, and those quadrants have a value of -π < θ < 0 in those areas. In addition to this, the general argument of the complex number is written as 2nπ+θ.

General Argument Of Complex Number = 2nπ + θ

Therefore, the argument of a complex number is derived from a trigonometric function; consequently, it possesses both the principle and the general argument.

Conclusion:

The argument of a complex number can be used in a variety of contexts, including converting the complex number to its polar form and determining the connection between the complex number’s real and imaginary components. Both of these tasks are examples of applications. The argument value of a complex number is the angle, which can be used to determine whether the real part or the imaginary part is the more significant component of the whole.

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