Class Central is learner-supported. When you buy through links on our site, we may earn an affiliate commission.

YouTube

Using Complex Numbers - Comprehensive Course on De Moivre's Theorem, Argand Diagrams, and Complex Analysis

Eddie Woo via YouTube

Overview

Coursera Flash Sale
40% Off Coursera Plus for 3 Months!
Grab it
Explore comprehensive video tutorials covering advanced complex number theory and applications. Master De Moivre's Theorem for proving trigonometric identities and finding complex roots, understand the Conjugate Root Theorem, and learn to work with Argand diagrams and locus problems. Develop skills in representing complex numbers as points and vectors, including geometric interpretations of addition, subtraction, and multiplication operations. Study triangle inequalities, graph complex inequalities and regions on the complex plane, and analyze arguments and moduli geometrically. Practice solving complex polynomial equations, work with roots of unity, and apply complex numbers to prove trigonometric identities using binomial expansions. Examine real-world applications including atomic and string theory contexts, tackle HSC-level examination problems, and explore advanced topics like the Basel Problem. Learn to sketch complex functions, find maximum and minimum values of moduli, and solve geometric problems involving squares and equilateral triangles using complex number methods. Build proficiency in converting between rectangular and polar forms, understanding fundamental theorem of algebra applications, and manipulating complex expressions algebraically and geometrically.

Syllabus

Using De Moivre's Theorem to Prove Trigonometric Identity
Understanding & Applying the Conjugate Root Theorem
Argand Diagram / Locus Question
Interesting Complex Polynomial Question (1 of 2: Factorisation)
Interesting Complex Polynomial Question (2 of 2: Trigonometric Result)
Complex Numbers as Points (1 of 4: Geometric Meaning of Addition)
Complex Numbers as Points (2 of 4: Geometric Meaning of Subtraction)
Complex Numbers as Points (3 of 4: Geometric Meaning of Multiplication)
Complex Numbers as Points (4 of 4: Second Multiplication Example)
De Moivre's Theorem
How to graph the locus of |z-1|=1
Complex Numbers as Vectors (1 of 3: Introduction & Addition)
Complex Numbers as Vectors (2 of 3: Subtraction)
Complex Numbers as Vectors (3 of 3: Using Geometric Properties)
Complex Roots (2 of 5: Expanding in Rectangular Form)
The Triangle Inequalities (1 of 3: Sum of Complex Numbers)
Graphs in the Complex Plane (1 of 4: Introductory Examples)
The Triangle Inequalities (2 of 3: Discussing Specific Cases)
The Triangle Inequalities (3 of 3: Difference of Complex Numbers)
Graphs in the Complex Plane (2 of 4: Graphing Complex Inequalities)
Graphs in the Complex Plane (3 of 4 : Shifting the Point of Reference)
Graphs in the Complex Plane (4 of 4: Where is the argument measured from?)
Further Graphs on the Complex Plane (1 of 3: Geometrical Representation of Moduli)
Further Graphs on the Complex Plane (2 of 3: Algebraically verifying Graphs concerning the Moduli)
Further Graphs on the Complex Plane (3 of 3: Geometrical Representation of Arguments)
Graphs on the Complex Plane (3 of 4: Geometry of arg(z)-arg(z-1))
Graphs on the Complex Plane (4 of 4: Exploring how the argument traced the graph)
Graphs on the Complex Plane [Continued] (1 of 4: What's behind the graph?)
Graphs on the Complex Plane [Continued] (2 of 4: Finding Regions of Inequality by Testing Points)
Using Inverse tan to find arguments? (1 of 2: Why it doesn't work... Sometimes)
Complex Roots (1 of 5: Introduction)
Complex Roots (3 of 5: Through Polar Form Using De Moivre's Theorem)
Using Inverse tan to find arguments? (2 of 2: Why it works... Sometimes)
Complex Roots (4 of 5: Through Polar Form Generating Solutions)
Complex Roots (5 of 5: Flowing Example - Solving z^6=64)
Complex Conjugate Root Theorem (1 of 4: Using DMT and Polar Form to solve for Complex Roots)
Complex Conjugate Root Theorem (2 of 4: Introduction to the Conjugate Root Theorem)
Complex Conjugate Root Theorem (3 of 4: Geometrical Shape represented by Conjugate Root Theorem)
Complex Conjugate Root Theorem (4 of 4: Using Factorisation to find patterns with Roots of Unity)
DMT and Trig Identities (1 of 4: Deriving multi-angle identities with compound angles)
DMT and Trig Identities (2 of 4: Using De Moivre's Theorem and Binomial Expansions)
DMT and Trig Identities (3 of 4: Deriving tan expression from cos and sin)
DMT and Trig Identities (4 of 4: Using Multi-angle formula to solve polynomials)
Complex Numbers (1 of 6: Solving Harder Complex Numbers Questions) [Student requested problem]
Complex Numbers (2 of 6: Solving Harder Complex Numbers Questions) [Student Requested Problem]
Complex Numbers (3 of 6: Harder Complex Numbers Question) [Student Requested Problem]
Complex Numbers (4 of 6: Harder Complex Numbers Questions) [Student Requested Problem]
Complex Numbers (5 of 6: Complex Numbers Proofs [Using the Conjugate])
Complex Numbers (6 of 6: Finishing off the Proof)
Roots and Coefficients (1 of 3: Using DMT & Binomial Theorem to find identities)
Roots and Coefficients (2 of 3: Using Trigonometry to solve polynomial problems)
Roots and Coefficients (3 of 3: Using the results to find a relation in cosine)
Extension II Assessment Review (5 of 5: De Moivre's Theorem and Polynomials)
Why Complex Numbers? (1 of 5: Atoms & Strings)
Why Complex Numbers? (2 of 5: Impossible Roots)
Why Complex Numbers? (3 of 5: The Imaginary Unit)
Why Complex Numbers? (4 of 5: Turning the key)
Why Complex Numbers? (5 of 5: Where to now?)
Complex Arithmetic (1 of 2: Addition, Subtraction & Multiplication)
Complex Arithmetic (2 of 2: Division)
Factorisation with Complex Numbers
Vectors (1 of 4: Outline of vectors and their ability to represent complex number)
Vectors (2 of 4: Representing addition & subtraction of complex numbers with vectors)
Vectors (3 of 4: Geometrically representing multiplication of complex numbers with vectors)
Vectors (4 of 4: Outlining the usefulness of vectors in representing geometry)
Curves and Regions on the Complex Plane (1 of 4: Introductory example plotting |z|=5 geometrically)
Curves and Regions on the Complex Plane (2 of 4: Deciphering terminology to plot complex numbers)
Curves and Regions on the Complex Plane (3 of 4: Simplifying expressions to plot on a complex plane)
Curves and Regions on the Complex Plane (4 of 4: Plotting simultaneous shifted complex numbers)
Further Curves and Regions (1 of 5: Why does Sine & the Sine Rule produce an ambiguous case?)
Further Curves and Regions (2 of 5: Finding the Range of |z| )
Further Curves and Regions (3 of 5: Finding the range of arg z)
Further Curves and Regions (4 of 5: Geometrical expression of expressions of arg)
Further Curves and Regions (5 of 5: Using Circle properties to graph an expression of args)
DMT & Complex Roots (1 of 4: Reviewing geometrical expression of arg equations)
DMT & Complex Roots (2 of 4: Using DMT to find roots of a complex polynomial)
DMT & Complex Roots (3 of 4: Using the fundamental theorem of algebra to justify number of roots)
DMT & Complex Roots (4 of 4: Solving for roots of a complex number taking advantage of DMT)
Complex Roots (1 of 5: Observing Complex Conjugate Root Theorem through seventh roots of unity)
Complex Roots (2 of 5: Using Trigonometrical Identities & Conjugates to solve an equation)
Complex Roots (3 of 5: Using DMT to solve an equation of roots of unity)
Complex Roots (4 of 5: Using Polynomial Identities to prove unity identities)
Complex Roots (5 of 5: Using Geometric Progression to find factors of ω^n - 1)
DMT and Trig Identities (1 of 4: Noticing a pattern in natural numbers)
DMT and Trig Identities (2 of 4: Using Trig expansion to find the sine triple angle formula)
DMT and Trig Identities (3 of 4: Using DMT and Polynomials to verify triple angle formula for sine)
DMT and Trig Identities (4 of 4: Using Trig Identities to solve polynomial equations)
HSC Question on Complex Numbers, Vectors & Triangle Area (1 of 2: Thinking geometrically)
HSC Question on Complex Numbers, Vectors & Triangle Area (2 of 2: Manipulating trigonometric terms)
HSC Question on Complex Numbers, Vectors & Polynomials (1 of 2: How to "explain")
HSC Question on Complex Numbers, Vectors & Polynomials (2 of 2: Combining results)
2016 HSC - Complex Numbers on Unit Circle (1 of 2: Considering Re & Im Parts)
2016 HSC - Complex Numbers on Unit Circle (2 of 2: Evaluating the arguments)
2016 HSC - Complex Identity Proof (1 of 3: Convert to polar form)
2016 HSC - Complex Identity Proof (2 of 3: Using binomial theorem)
2016 HSC - Complex Identity Proof (3 of 3: Combining results)
Semi Circles on Argand Diagrams (3 of 3: Oblique example)
Semi Circles on Argand Diagrams (2 of 3: Graphing the locus)
Semi Circles on Argand Diagrams (1 of 3: Relating the angles)
Algebraic Proof for Opposing Rays (3 of 3: Testing cases)
Algebraic Proof for Opposing Rays (2 of 3: Generating the equation)
Algebraic Proof for Opposing Rays (1 of 3: Foundational knowledge)
cos⁴θ Identity
Graphs in the Complex Plane (3 of 3: Opposing rays)
Graphs in the Complex Plane (2 of 3: Algebraic method)
Graphs in the Complex Plane (1 of 3: Perpendicular bisector - visual method)
Complex Polynomial Identity Question (4 of 4: Roots & coefficients)
Complex Polynomial Identity Question (3 of 4: de Moivre's Theorem)
Complex Polynomial Identity Question (2 of 4: Difference of cubes)
Complex Polynomial Identity Question (1 of 4: Quadratic factors)
Sum & Product of Cosines (3 of 3: Drawing ℝ conclusions)
Sum & Product of Cosines (2 of 3: Simplifying with conjugates)
Sum & Product of Cosines (1 of 3: 9th roots of unity)
Nth Roots of a ℂ Number (2 of 2: Example problem)
Nth Roots of a ℂ Number (1 of 2: General form)
Roots of Unity (2 of 2: Insights from polar & exponential forms)
Roots of Unity (1 of 2: Evaluating the cube roots)
Complex Conjugate Root Theorem (2 of 2: Other conjugate properties)
Complex Conjugate Root Theorem (1 of 2: Conjugate of a sum)
Solving Higher Degree Trigonometric Equations (3 of 3: Finding solutions)
Solving Higher Degree Trigonometric Equations (2 of 3: Combining results into proof)
Solving Higher Degree Trigonometric Equations (1 of 3: Initial use of de Moivre's Theorem)
Equations with Complex Solutions (2 of 2: Solving & factorising)
Equations with Complex Solutions (1 of 2: Relation to square roots)
Polynomials with Trigonometric Solutions (3 of 3: Simplifying with identities)
Polynomials with Trigonometric Solutions (2 of 3: Substitute & solve)
Polynomials with Trigonometric Solutions (1 of 3: de Moivre's Theorem)
Trigonometric Expansions from Complex Numbers (3 of 3: General compound angles)
Trigonometric Expansions from Complex Numbers (2 of 3: Double angle results)
Trigonometric Expansions from Complex Numbers (1 of 3: Concept map)
Using de Moivre's Theorem - example question (2 of 2: Purely imaginary)
Using de Moivre's Theorem - example question (1 of 2: Purely real)
Proving de Moivre's Theorem (2 of 2: Derivation & example problem)
Proving de Moivre's Theorem (1 of 2: Prologue)
Arcs on the Complex Plane (1 of 4: Review questions)
Arcs on the Complex Plane (3 of 4: Identifying length and direction)
Arcs on the Complex Plane (2 of 4: Exploring circle properties)
Arcs on the Complex Plane (4 of 4: Cartesian equation)
Angles in the Same Segment
Algebraic Approach for Major Arc (1 of 2: Foundational steps)
Algebraic Approach for Major Arc (2 of 2: Identifying intercept & equation)
Max/Min Value of |z| (1 of 2: Geometric solution)
Max/Min Value of |z| (2 of 2: Triangle inequality)
Investigating de Moivre's Theorem (1 of 3: Why must we be cautious?)
Investigating de Moivre's Theorem (2 of 3: Infinite values for i-th powers?!)
Investigating de Moivre's Theorem (3 of 3: Proof by mathematical induction)
Varying |z| & Argz on a Locus
Maximising Sum of Moduli (1 of 3: Geometric approach)
Maximising Sum of Moduli (2 of 3: Differentiation)
Maximising Sum of Moduli (3 of 3: Interpreting stationary points)
Sketching (z-1)÷(z-i) (1 of 2: When it's real)
Sketching (z-1)÷(z-i) (2 of 2: When it's imaginary)
Complex Numbers Exam Review (1 of 4: Visualising & Manipulating Arithmetic)
Complex Numbers Exam Review (2 of 4: Proving i^i is real, identity proof)
Complex Numbers Exam Review (3 of 4: Cube roots of unity)
Complex Numbers Exam Review (4 of 4: Locus; polynomial identity)
Prove arg(z₁z₂) = arg(z₁+z₂)² (1 of 2: Preliminary thoughts)
Prove arg(z₁z₂) = arg(z₁+z₂)² (2 of 2: Geometric approach)
Complex Geometry - Square Problem (1 of 2: Complex numbers → vectors)
Complex Geometry - Square Problem (2 of 2: Vectors → complex numbers)
Complex Geometry - Equilateral Triangle (3 of 3: Vector proof)
Complex Geometry - Equilateral Triangle (2 of 3: Algebraic method)
Complex Geometry - Equilateral Triangle (1 of 3: Arithmetic proof)
The Basel Problem (9 of 9: Squeeze law)
The Basel Problem (8 of 9: Returning to trigonometric terms)
The Basel Problem (7 of 9: Manipulating the polynomial integral)
The Basel Problem (5 of 9: Telescoping sum)
The Basel Problem (6 of 9: Equations → inequalities)
The Basel Problem (4 of 9: Introducing x² to the integrand)
The Basel Problem (3 of 9: Integration by *different* parts)
The Basel Problem (1 of 9: Prologue)
The Basel Problem (2 of 9: Recurrence relation)
Centre of a Major Arc (5 of 5: Algebraic proof)
Centre of a Major Arc (4 of 5: Inscribed equilateral triangle)
Centre of a Major Arc (3 of 5: Using trigonometric & vectors)
Centre of a Major Arc (2 of 5: Finding centre and radius)
Centre of a Major Arc (1 of 5: Evaluating internal angle)
How to graph a region on the complex plane
Three ways to find a parallelogram's area

Taught by

Eddie Woo

Reviews

Start your review of Using Complex Numbers - Comprehensive Course on De Moivre's Theorem, Argand Diagrams, and Complex Analysis

Never Stop Learning.

Get personalized course recommendations, track subjects and courses with reminders, and more.

Someone learning on their laptop while sitting on the floor.