# Quaternion

In mathematics, the quaternion number system extends the complex numbers. Quaternions were first described by the Irish mathematician William Rowan Hamilton in 1843 and applied to mechanics in three-dimensional space. Hamilton defined a quaternion as the quotient of two directed lines in a three-dimensional space, or, equivalently, as the quotient of two vectors. Multiplication of quaternions is noncommutative. Quaternions are generally represented in the form where a, b, c, and d are real numbers; and i, j, and k are the basic quaternions. Quaternions are used in pure mathematics, but also have practical uses in applied mathematics, particularly for calculations involving three-dimensional rotations, such as in three-dimensional computer graphics, computer vision, and crystallographic texture analysis. They can be used alongside other methods of rotation, such as Euler angles and rotation matrices, or as an alternative to them, depending on the application. In modern mathematical language, quaternions form a four-dimensional associative normed division algebra over the real numbers, and therefore a ring, being both a division ring and a domain. The algebra of quaternions is often denoted by H (for Hamilton), or in blackboard bold by It can also be given by the Clifford algebra classifications In fact, it was the first noncommutative division algebra to be discovered. According to the Frobenius theorem, the algebra is one of only two finite-dimensional division rings containing a proper subring isomorphic to the real numbers; the other being the complex numbers. These rings are also Euclidean Hurwitz algebras, of which the quaternions are the largest associative algebra (and hence the largest ring). Further extending the quaternions yields the non-associative octonions, which is the last normed division algebra over the real numbers. (The sedenions, the extension of the octonions, have zero divisors and so cannot be a normed division algebra.) The unit quaternions can be thought of as a choice of a group structure on the 3-sphere S3 that gives the group Spin(3), which is isomorphic to SU(2) and also to the universal cover of SO(3). (Wikipedia).

Solve an equation with a rational term

ðŸ‘‰ Learn how to solve rational equations. A rational expression is an expression in the form of a fraction where the numerator and/or the denominator are/is an algebraic expression. There are many ways to solve rational expressions, one of the ways is by multiplying all the individual ratio

From playlist How to Solve Rational Equations with Trinomials

Math tutorial for solving an equation with a fractional exponent

ðŸ‘‰ Learn how to deal with Rational Powers or Exponents. Exponents are shorthand for repeated multiplication of the same thing by itself. This process of using exponents is called "raising to a power", where the exponent is the "power". Rational exponents are exponents that are fractions. To

From playlist Solve Equations with Fractional Exponents

Learn how to solve a rational equation and identify the extraneous solutions

ðŸ‘‰ Learn how to solve rational equations. A rational expression is an expression in the form of a fraction where the numerator and/or the denominator are/is an algebraic expression. There are many ways to solve rational expressions, one of the ways is by multiplying all the individual ratio

From playlist How to Solve Rational Equations with Trinomials

What are the restrictions we put on a rational expression

ðŸ‘‰ Learn about solving rational equations. A rational expression is an expression in the form of a fraction where the numerator and/or the denominator are/is an algebraic expression. There are many ways to solve rational equations, one of the ways is by multiplying all the individual ration

From playlist How to Solve Rational Equations | Learn About

Learn how to solve a rational equation and check your solutions

ðŸ‘‰ Learn how to solve rational equations. A rational expression is an expression in the form of a fraction where the numerator and/or the denominator are/is an algebraic expression. There are many ways to solve rational expressions, one of the ways is by multiplying all the individual ratio

From playlist How to Solve Rational Equations with Trinomials

Solve rational equation with 1 real solution

ðŸ‘‰ Learn how to solve rational equations. A rational expression is an expression in the form of a fraction where the numerator and/or the denominator are/is an algebraic expression. There are many ways to solve rational expressions, one of the ways is by multiplying all the individual ratio

From playlist How to Solve Rational Equations with Trinomials

Learn how to solve an equation with a rational power by squaring both side

ðŸ‘‰ Learn how to deal with Rational Powers or Exponents. Exponents are shorthand for repeated multiplication of the same thing by itself. This process of using exponents is called "raising to a power", where the exponent is the "power". Rational exponents are exponents that are fractions. To

From playlist Solve Equations with Fractional Exponents

How to solve an equation with an expression raised to a fractional power

ðŸ‘‰ Learn how to deal with Rational Powers or Exponents. Exponents are shorthand for repeated multiplication of the same thing by itself. This process of using exponents is called "raising to a power", where the exponent is the "power". Rational exponents are exponents that are fractions. To

From playlist Solve Equations with Fractional Exponents

Learn to solve an equation raised to a rational power

ðŸ‘‰ Learn how to deal with Rational Powers or Exponents. Exponents are shorthand for repeated multiplication of the same thing by itself. This process of using exponents is called "raising to a power", where the exponent is the "power". Rational exponents are exponents that are fractions. To

From playlist Solve Equations with Fractional Exponents

Geometric Algebra - Rotors and Quaternions

In this video, we will take note of the even subalgebra of G(3), see that it is isomorphic to the quaternions and, in particular, the set of rotors, themselves in the even subalgebra, correspond to the set of unit quaternions. This brings the entire subject of quaternions under the heading

From playlist Math

Set Theory (Part 14b): Quaternions and 3D Rotations

No background in sets needed for this video - learn about the foundations of quaternions, derivation of the Hamilton product, and their application to 3D rotations. We will also see how dot and cross products are related to quaternion math. This video will be of particular interest to comp

From playlist Set Theory by Mathoma

Computing Euler Angles: Tracking Attitude Using Quaternions

In this video we continue our discussion on how to track the attitude of a body in space using quaternions. The quaternion method is similar to the Euler Kinematical Equations and Poissonâ€™s Kinematical Equations in that it consumes rate gyro information to compute Euler angles. However,

From playlist Flight Mechanics

Quaternions: Extracting the Dot and Cross Products

The most important operations upon vectors include the dot and cross products and are indispensable for doing physics and vector calculus. The dot product gives a quick way to check whether vectors are orthogonal and the cross product calculates a new vector orthogonal to both its inputs.

From playlist Quaternions

Lie Groups and Lie Algebras: Lesson 2 - Quaternions

This video is about Lie Groups and Lie Algebras: Lesson 2 - Quaternions We study the algebraic nature of quaternions and cover the ideas of an algebra and a field. Later we will discover how quaternions fit into the description of the classical Lie Groups. NOTE: An astute viewer noted th

From playlist Lie Groups and Lie Algebras

Visualizing quaternions (4d numbers) with stereographic projection

How to think about this 4d number system in our 3d space. Part 2: https://youtu.be/zjMuIxRvygQ Interactive version of these visuals: https://eater.net/quaternions Help fund future projects: https://www.patreon.com/3blue1brown An equally valuable form of support is to simply share some of t

From playlist Explainers

Set Theory (Part 14c): More on the Quaternions

No background in sets required for this video. In this video, we will learn how the quaternions can be thought of as pairings of complex numbers. We also will show how the quaternions can be written as a 2x2 complex matrix as opposed to a 4x4 real matrix and how the unit quaternions form t

From playlist Set Theory

Quaternions as 4x4 Matrices - Connections to Linear Algebra

In math, it's usually possible to view an object or concept from many different (but equivalent) angles. In this video, we will see that the quaternions may be viewed as 4x4 real-valued matrices of a special form. What is interesting here is that if you know how to multiply matrices, you a

From playlist Quaternions

Multiplying two rational expressions with polynomials

Learn how to multiply rational expressions. A rational expression is an expression in the form of a fraction where the numerator and/or the denominator are/is an algebraic expression. To multiply two rational expressions, we use the distributive property to multiply both numerators togethe

From playlist Multiply Rational Expressions (Trinomials) #Rational

Quaternions EXPLAINED Briefly

This is a video I have been wanting to make for some time, in which I discuss what the quaternions are, as mathematical objects, and how we do calculations with them. In particular, we will see how the fundamental equation of the quaternions i^2=j^2=k^2=ijk=-1 easily generates the rule for

From playlist Quaternions